High-performance near-infrared harvesting transparent luminescent solar concentrator

Abstract

The present invention provides a transparent luminescent solar concentrator (TLSC), the TLSC comprising a luminophore and a waveguide for guiding light emitted from the luminophore. The TLSC has a light utilization efficiency (LUE) greater than or equal to about 1.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 963,455, filed on January 20, 2020. The entire disclosure of the above application is incorporated herein by reference.

[0003] Government support

[0004] This invention was made with Government support from the National Science Foundation under Award 1702591. The Government has certain rights in this invention. Technical Field

[0005] The present disclosure relates to transparent luminescent solar concentrators. Background Art

[0006] This section provides background information related to the present disclosure which is not necessarily prior art.

[0007] Incorporating solar energy harvesting systems into buildings, including building envelopes, windows and panels, and electronic displays, provides a practical way to utilize renewable solar energy. Solar energy harvesting systems are widely adopted in buildings; however, the difficulty of installing traditional solar modules on and around buildings has severely hampered their application due to cost, building impedance, and most importantly, aesthetic factors.

[0008] The concept of luminescent solar concentrators (LSCs), including transparent LSCs (TLSCs), is well known, and recent advances in the efficiency of phosphorescent and fluorescent emitters have increased the efficiency of LSC systems to 7.1%. While optical funneling of light limits the overall system conversion efficiency to below 10% (without an LSC stack), it can significantly reduce the required area of expensive solar cells, thereby lowering overall installation costs and increasing the ratio of power generation to solar cell surface area. Due to the high costs of glass and real estate, which impact the balance of component and system costs, respectively, such LSCs have rarely been adopted in practical solar power plants, despite their increasing performance and potential for low component costs. Furthermore, there has been interest in using LSCs as windows in buildings and vehicles, as well as displays in electronic devices. However, many of these systems have been limited to absorption and emission (luminescence) in the visible portion of the spectrum, hindering widespread adoption of such devices. For example, the purpose of windows is to provide natural light and a view, and most people prefer not to work behind tinted glass. Therefore, widespread adoption of high levels of colorless transparency is desirable.

[0009] The performance of LSCs can be understood in terms of component efficiencies: emitter photoluminescence efficiency (quantum yield), solar spectrum absorption efficiency, waveguide (trapping) efficiency, solar cell efficiency, and transport (reabsorption) efficiency. The highest performance LSCs utilize phosphorescent organic molecules or mixtures of multiple fluorophores (such as quantum dots or organic dyes) to reduce reabsorption (Stokes shift) losses and increase overall absorption efficiency across the spectrum. Some of the highest reported efficiencies (6-7%) are for relatively small panels (less than 0.1 μm). 2 ), because larger LSCs size suffers from substantial reabsorption losses, limiting the efficiency to below 5%.

[0010] It has long been recognized that LSCs are most limited by reabsorption losses, especially for larger plate sizes. Indeed, research on LSCs has focused on reducing these reabsorption losses by increasing the Stokes shift of organic phosphors. Optimization of multiple dyes to artificially increase the Stokes shift or resonance shift is only applicable to pure film dye layers with thicknesses less than a few micrometers.

[0011] Previous efforts to build transparent solar harvesting architectures have focused on (1) semi-transparent thin-film photovoltaics that typically have severe tinting, or limited transmission, or have an intrinsic trade-off between efficiency and transparency, (2) LSCs containing colored chromophores that absorb or emit in the visible, (3) optical systems that use wavelength-dependent optics that only collect direct light and require sun tracking, or (4) have unacceptable levels of haze. All of these approaches have been severely limited in their potential for window applications due to aesthetic properties, bulkiness, or fairly limited transparency. These approaches suffer from an intrinsic trade-off between power conversion efficiency (PCE) and visible transparency (VT), as these two parameters cannot be optimized simultaneously in conventional devices. Architectural adoption is further hampered by the fact that typical organic photovoltaics (PVs) have peak absorption within the visible spectrum, resulting in poor color rendering index (CRI), high tinting, and poor natural lighting quality. Therefore, there remains a need to develop efficient, high-performance TLSCs that provide natural, colorless light. Summary of the Invention

[0012] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0013] This technology provides a high-performance near-infrared harvesting transparent luminescent solar concentrator.

[0014] In various aspects, the present technology provides a transparent luminescent solar concentrator (TLSC) comprising a luminophore and a waveguide that guides light emitted from the luminophore, wherein the TLSC has a light utilization efficiency (LUE) greater than or equal to about 1.

[0015] In one aspect, the TLSC has an average visible transmission (AVT) greater than or equal to about 50% and a color rendering index (CRI) greater than or equal to about 80 at normal incidence to the waveguide.

[0016] In one aspect, the TLSC has a power conversion efficiency (PCE) greater than or equal to about 1% and a |b less than or equal to about 25. * |value.

[0017] In one aspect, the TLSC has an average visible transmission (AVT) greater than or equal to about 60%.

[0018] In one aspect, the light emitter is embedded within the waveguide, disposed directly on the waveguide, or provided in a film disposed on the waveguide.

[0019] In one aspect, the TLSC further comprises a photovoltaic assembly operably coupled to the waveguide.

[0020] In one aspect, the luminophore has a strongest absorbance maximum and a strongest peak emission at greater than or equal to about 650 nm.

[0021] In one aspect, the TLSC has a haze of less than or equal to about 10%.

[0022] In one aspect, the luminophore is a non-fullerene acceptor, boron-dipyrromethene (BODIPY), or a combination thereof.

[0023] In one aspect, the luminophore is a non-fullerene acceptor, and the non-fullerene acceptor is 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2″″,3″″:4″′,5″′]thieno[2″′,3″′:4″,5″]pyrano[2″,3″:4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4- hexylphenyl)-4,9-dihydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof.

[0024] In one aspect, the TLSC further includes a second light emitter and a second waveguide that guides light emitted from the second light emitter, wherein the second waveguide is positioned adjacent to the waveguide such that the waveguide receives light transmitted through the second waveguide, and wherein the waveguide and the second waveguide are separated by a gap filled with air or filled with a visible transparent material.

[0025] In one aspect, the visually transparent material has a refractive index (n) less than or equal to about 1.3.

[0026] In one aspect, the second light emitter has a quantum yield (QY) greater than or equal to about 50%.

[0027] In one aspect, the second luminophore has a strongest maximum absorbance less than or equal to about 450 nm and a strongest peak emission greater than or equal to about 650 nm.

[0028] In one aspect, the second light emitter comprises nanoclusters.

[0029] In one aspect, the waveguide and the second waveguide are configured such that incident light first passes through the second waveguide and then through the first waveguide.

[0030] In various aspects, the present technology also provides a transparent luminescent solar concentrator (TLSC) comprising a luminophore and a waveguide for guiding light emitted from the luminophore, wherein the TLSC has a power conversion efficiency (PCE) greater than or equal to about 1% and a |b less than or equal to about 25. * |value.

[0031] In one aspect, the TLSC has an average visible light transmission greater than or equal to about 50% and a color rendering index (CRI) greater than or equal to about 80 at normal incidence to the waveguide.

[0032] In one aspect, the TLSC has a light utilization efficiency (LUE) greater than or equal to about 1.

[0033] In one aspect, the TLSC has an average visible transmission (AVT) greater than or equal to about 50%.

[0034] In one aspect, the light emitter is embedded within the waveguide, disposed directly on the waveguide, or provided in a film disposed on the waveguide.

[0035] In one aspect, the TLSC further comprises a photovoltaic assembly operably coupled to the waveguide.

[0036] In one aspect, the luminophore has a maximum absorbance and a peak emission at greater than or equal to about 650 nm.

[0037] In one aspect, the TLSC has a haze of less than or equal to about 10%.

[0038] In one aspect, the luminophore is a non-fullerene acceptor, boron-dipyrromethene (BODIPY), or a combination thereof.

[0039] In one aspect, the luminophore is a non-fullerene acceptor, the non-fullerene acceptor being CO i 8DFIC, 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4- hexylphenyl)-4,9-dihydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof.

[0040] In one aspect, the TLSC further includes a second light emitter and a second waveguide that guides light emitted from the second light emitter, wherein the second waveguide is positioned adjacent to the waveguide such that the waveguide receives light transmitted through the second waveguide, and wherein the waveguide and the second waveguide are separated by a gap filled with air or filled with a visible transparent material.

[0041] In one aspect, the visually transparent material has a refractive index (n) less than or equal to about 1.3.

[0042] In one aspect, the second light emitter has a quantum yield (QY) greater than or equal to about 50%.

[0043] In one aspect, the second luminophore has a strongest maximum absorbance at less than or equal to about 450 nm and a strongest peak emission at greater than or equal to about 650 nm.

[0044] In one aspect, the second light emitter comprises nanoclusters.

[0045] In one aspect, the waveguide and the second waveguide are configured such that incident light first passes through the second waveguide and then through the first waveguide.

[0046] In various aspects, the present technology also provides a transparent luminescent solar concentrator (TLSC) comprising a luminophore comprising polythiophene having both a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm, and a waveguide for guiding light emitted from the luminophore.

[0047] In one aspect, the TLSC has a light utilization efficiency (LUE) greater than or equal to about 1, an average visible transmission (AVT) greater than or equal to about 50%, and a color rendering index (CRI) greater than or equal to about 80 at normal incidence to the waveguide.

[0048] In one aspect, the TLSC has a power conversion efficiency (PCE) greater than or equal to about 1% and a |b less than or equal to about 25. * |value.

[0049] In one aspect, the light emitter is embedded within the waveguide, disposed directly on the waveguide, or provided in a film disposed on the waveguide.

[0050] In one aspect, the TLSC further comprises a photovoltaic assembly operably coupled to the waveguide.

[0051] In one aspect, the TLSC has a haze of less than or equal to about 10%.

[0052] In one aspect, the polythiophene is 2,2′-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2′,3′:4,5]thieno[2,3-d]thieno[2″″,3″″:4″′,5″′]thieno[2″′,3″′:4″,5″]pyrano[2″,3″:4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4- hexylphenyl)-4,9-dihydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof.

[0053] In one aspect, the TLSC further comprises a second luminophore comprising boron-dipyrromethene (BODIPY) having both a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm, wherein the waveguide guides light emitted from the luminophore and the second luminophore.

[0054] In one aspect, the TLSC further comprises a second light emitter and a second waveguide that guides light emitted from the second light emitter, wherein the second waveguide is positioned adjacent to the waveguide such that the waveguide receives light transmitted through the second waveguide, and wherein the waveguide and the second waveguide are separated by a layer of air or a layer comprising a visually transparent material.

[0055] In one aspect, the visually transparent material has a refractive index (n) less than or equal to about 1.3.

[0056] In one aspect, the second light emitter has a quantum yield (QY) greater than or equal to about 50%.

[0057] In one aspect, the second luminophore has a strongest maximum absorbance at less than or equal to about 450 nm and a strongest peak emission at greater than or equal to about 650 nm.

[0058] In one aspect, the second light emitter comprises nanoclusters.

[0059] In one aspect, the waveguide and the second waveguide are configured such that incident light first passes through the second waveguide and then through the first waveguide.

[0060] In one aspect, the TLSC further comprises a third luminophore comprising boron-dipyrromethene (BODIPY) having both a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm, wherein the waveguide guides light emitted from the luminophore and the third luminophore.

[0061] In certain aspects, the present technology provides a transparent luminescent solar concentrator (TLSC) comprising a luminophore comprising boron-dipyrromethene (BODIPY) having a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm, and a waveguide for guiding light emitted from the luminophore.

[0062] In one aspect, the TLSC has a light utilization efficiency (LUE) greater than or equal to about 1, an average visible transmission (AVT) greater than or equal to about 50%, and a color rendering index (CRI) greater than or equal to about 80 at normal incidence to the waveguide.

[0063] In one aspect, the TLSC has a power conversion efficiency (PCE) greater than or equal to about 1% and a |b less than or equal to about 25. * |value.

[0064] In one aspect, the light emitter is embedded within the waveguide, disposed directly on the waveguide, or provided in a film disposed on the waveguide.

[0065] In one aspect, the TLSC further comprises a photovoltaic assembly operably coupled to the waveguide.

[0066] In one aspect, the TLSC has a haze of less than or equal to about 10%.

[0067] In one aspect, the TLSC further includes a second luminophore, the second luminophore comprising a polythiophene having both the strongest maximum absorbance and the strongest peak emission at about 650 nm or greater, wherein the polythiophene is 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2",3"":4",5"']thieno[2",3"':4",5"]pyrano[2",3":4',5']thieno[2',3':4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dithiophene Hydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof, wherein the waveguide guides light emitted from the light emitter and the second light emitter.

[0068] In one aspect, the TLSC further comprises a second light emitter and a second waveguide that guides light emitted from the second light emitter, wherein the second waveguide is positioned adjacent to the waveguide such that the waveguide receives light transmitted through the second waveguide, and wherein the waveguide and the second waveguide are separated by a layer of air or a layer comprising a visually transparent material.

[0069] In one aspect, the visually transparent material has a refractive index (n) less than or equal to about 1.3.

[0070] In one aspect, the second light emitter has a quantum yield (QY) greater than or equal to about 50%.

[0071] In one aspect, the second luminophore has a strongest maximum absorbance at less than or equal to about 450 nm and a strongest peak emission at greater than or equal to about 650 nm.

[0072] In one aspect, the second light emitter comprises nanoclusters.

[0073] In one aspect, the waveguide and the second waveguide are configured such that incident light first passes through the second waveguide and then through the first waveguide.

[0074] In one aspect, the TLSC further includes a third light-emitting body, the third light-emitting body comprising polythiophene, which has the strongest maximum absorbance and the strongest peak emission at greater than or equal to about 650 nm, wherein the polythiophene is 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2″″,3″″:4″′,5″′]thieno[2″′,3″′:4″,5″]pyrano[2″,3″:4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dithiophene Hydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile](IEICO-4F), or a combination thereof, wherein the waveguide guides light emitted from the light emitter and the third light emitter.

[0075] In various aspects, the present technology provides a transparent luminescent solar concentrator (TLSC) comprising a first waveguide that guides light emitted from a first light emitter, the first waveguide having a first light receiving surface and an opposite first light transmitting surface; and a second waveguide that guides light emitted from a second light emitter, the second waveguide having a second light receiving surface and an opposite second light transmitting surface, wherein the first waveguide and the second waveguide are separated by a transparent material or air layer having a refractive index (n) less than or equal to about 1.3, and wherein one of the first light emitter or the second light emitter has a strongest maximum absorbance at less than or equal to about 450 nm and a strongest peak emission at greater than or equal to about 650 nm, and the other of the first light emitter or the second light emitter has a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm.

[0076] In one aspect, the first light receiving surface of the first waveguide is configured to receive incident light, and the first luminophore has a maximum absorbance at less than or equal to about 450 nm and a maximum peak emission at greater than or equal to about 650 nm.

[0077] In one aspect, the first light emitter has a quantum yield (QY) greater than or equal to about 50%.

[0078] In one aspect, the first luminophore has a strongest maximum absorbance at less than or equal to about 450 nm and a strongest peak emission at greater than or equal to about 650 nm.

[0079] In one aspect, the first light emitter comprises nanoclusters.

[0080] In one aspect, the second light emitter comprises polythiophene, boron-dipyrromethene (BODIPY), or a combination thereof, which has a strongest maximum absorbance and a strongest peak emission at greater than or equal to about 650 nm.

[0081] In one aspect, the second light emitting body comprises a polythiophene, wherein the polythiophene is 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2″″,3″″:4″′,5″′]thieno[2″′,3″′:4″,5″]pyrano[2″,3″:4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i 8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4- hexylphenyl)-4,9-dihydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof.

[0082] In one aspect, the TLSC has a light utilization efficiency (LUE) greater than or equal to about 1.

[0083] In one aspect, the TLSC has a power conversion efficiency (PCE) greater than or equal to about 1%.

[0084] In one aspect, the TLSC has a |b less than or equal to about 25. * |value.

[0085] In one aspect, the TLSC has a haze of less than or equal to about 10%.

[0086] In one aspect, the TLSC has an average visible transmission (AVT) greater than or equal to about 50%.

[0087] In one aspect, the TLSC has a color rendering index (CRI) greater than or equal to about 80 at normal incidence to the waveguide.

[0088] In one aspect, the TLSC further comprises a photovoltaic cell operably coupled to the first edge of the first waveguide and the second edge of the second waveguide.

[0089] In one aspect, the first light emitting body is embedded in the first waveguide, is directly disposed on the first waveguide, or is provided in a film disposed on the first waveguide; and the second light emitting body is embedded in the second waveguide, is directly disposed on the second waveguide, or is provided in a film disposed on the second waveguide.

[0090] Further areas of applicability will become apparent from the description provided herein.The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0092] Figure 1A is a schematic diagram of a TLSC according to various aspects of the present technology.

[0093] Figure 1B is a light according to various aspects of the present technology and Figure 1A Schematic diagram of the TLSC interaction.

[0094] Figure 2A is a schematic diagram of a TLSC in which a light emitter is embedded within a waveguide in accordance with various aspects of the present technology.

[0095] Figure 2B is a schematic diagram of a TLSC according to various aspects of the present technology, wherein the light emitter is disposed directly on the surface of the waveguide.

[0096] Figure 2C is a schematic diagram of a TLSC according to various aspects of the present technology, wherein a film containing a light emitter is disposed directly on the surface of a waveguide.

[0097] Figure 3A is a schematic diagram of a TLSC according to various aspects of the present technology, wherein photovoltaic cells are disposed on the edge of a waveguide, which edge may be rectangular, curved, or beveled.

[0098] Figure 3B is a schematic diagram of a TLSC in which a photovoltaic cell is disposed on a surface of a waveguide. According to various aspects of the present technology, an optional additional photovoltaic cell is disposed on at least one of a second surface of the waveguide and an edge of the waveguide.

[0099] Figure 3C is a schematic diagram of a TLSC in which a photovoltaic cell is disposed on a first surface of a waveguide and a wavelength-specific reflector is disposed on an edge of the waveguide. In accordance with various aspects of the present technology, an optional wavelength-dependent reflector is disposed on a second surface of the waveguide.

[0100] Figure 3D is a schematic diagram of a TLSC including a waveguide and a light emitter. According to various aspects of the present technology, a photovoltaic cell is disposed on a first surface of the waveguide, and a wavelength-specific reflector is disposed on an edge of the waveguide.

[0101] Figure 3E is a schematic diagram of a TLSC including a waveguide and a light emitter. According to various aspects of the present technology, a photovoltaic array is disposed at or near a surface of the waveguide.

[0102] Figure 3F is a schematic diagram of a TLSC including a waveguide and a light emitter. According to various aspects of the present technology, a photovoltaic array is embedded in a waveguide.

[0103] Figure 4 is a schematic diagram of an exemplary TLSC including a wavelength-dependent mirror in accordance with various aspects of the present technology.

[0104] Figure 5A is a schematic diagram of a transparent dual-band device in accordance with various aspects of the present technology.

[0105] Figure 5B yes Figure 5A A view of a transparent dual-band device taken along line 5B / 5C. According to various aspects of the present technology, a transparent dual-band device includes an air layer separating two waveguides.

[0106] Figure 5C yes Figure 5A A view of a transparent dual-band device taken along line 5B / 5C. According to various aspects of the present technology, a transparent dual-band device includes a layer comprising a transparent material separating two waveguides.

[0107] Figures 6A-6C Schematic diagram showing the working principle of a near-infrared (NIR) harvesting wavelength-selective transparent luminescent solar concentrator (TLSC), where the emitted deeper NIR photoluminescence is waveguided to an edge-mounted photovoltaic cell via total internal reflection, while visible light passes through ( Figure 6A ), CO i Molecular structure of 8DFIC ( Figure 6B ), and display CO i Images of the normalized absorption (blue) and emission (red) spectra of 8DFIC in chlorobenzene solution (solid line) and in a polymer matrix (dashed line) ( Figure 6C ).

[0108] Figures 7A-7B Shows CO i 8DFIC synthesis reaction ( Figure 7A ) and the molecular structure of ITIC ( Figure 7B ).

[0109] Figures 8A-8B shows CO embedded in two different polymer matrices i Images of the normalized absorption (blue) and emission (red) spectra of 8DFIC: Shandon (solid line) and Eukitt (dashed line) ( Figure 8A ) and CO in solutions, polymer matrix membranes, pure membranes, and particle aggregates. i Normalized absorption comparison of 8DFIC ( Figure 8B ).

[0110] Figures 9A-9C Shows different concentrations (Figure 50mgL -1 to 300mgL -1 CO (indicates solution concentration) i Images of the current density-voltage (JV) characteristics of TLSCs from 8DFIC, where all scans were measured under AM 1.5G illumination and all TLSCs were edge-mounted with Si PVs ( Figure 9A ), with different concentrations of CO i Average EQE of TLSCs of 8DFIC LSC (λ) spectrum, where the corresponding integrated J SC With Figure 9A The JV characteristic diagram shown in the figure extracts the J SC Good match ( Figure 9B ), and with different concentrations of CO i The normalized position of TLSCs of 8DFIC varies with EQE LSC The relationship between the peak change ( Figure 9C ).

[0111] Figures 10A-10C The absolute absorption and EQE of TLSCs with Cy7-NHS are shown LSC Spectral image ( Figure 10A ), with 150mgL -1 CO i Absolute absorption and EQE of TLSCs of 8DFIC LSC Spectral image ( Figure 10B ), and images of TLSCs reaching practical limits using GaAs as edge-mounted PV ( Figure 10C ).

[0112] Figures 11A-11B Shown are the EQEs of TLSCs with different edge-mounted PVs and G factors. LSC and average integrated J SC Comparison of images where the illuminant is Cy7-NHS ( Figure 11A ) and Co i 8DFIC( Figure 11B).

[0113] Figures 12A-12F The TLSC device is shown at each wavelength of cy7-NHS ( Figure 12A ) and different concentrations of Co i 8DFIC( Figures 12B-12F ) measured transmittance (T(λ)), reflectance (R(λ)), absorptivity (A(λ)=1-T(λ)-R(λ)), EQE LSC (λ) Spectrum and Photon Balance Check (EQE LSC (λ)+T(λ)+R(λ)≤1).

[0114] Figures 13A-13D Shows "150mgL -1 The transmittance (T(λ)), reflectance (R(λ)), absorptivity (A(λ)=1-T(λ)-R(λ)) and EQE of the TLSC device were measured at each wavelength. LSC (λ) Spectrum and Photon Balance Check (EQE LSC (λ)+T(λ)+R(λ)≤1)( Figure 13A ); CO in CIELAB color space i 8DFIC TLSCs color coordinates (a * ,b * ), where "300mgL -1 ” is strongly colored, the corresponding CO i 8DFIC TLSCs (edge-mounted with Si or GaAs PV) versus average visible transmittance (AVT) Figure 13B ); "150mgL" with edge-mounted GaAs PV -1 ” and “300mgL -1 Current density versus voltage (JV) characteristics of TLSCs, with the inset showing the average EQE of the same two edge-mounted GaAs PV TLSCs. LSC (λ) spectrum, where the corresponding integrated J SC and J extracted from the JV characteristic diagram SC Good match ( Figure 13C ); and photos of all TLSC installations ( Figure 13D ).

[0115] Figures 14A-14D The molecular structure of IEICO-4F is shown ( Figure 14A ), showing CO embedded in a polymer matrix (Eukitt i Images of the normalized absorption (blue) and emission (red) spectra of 8DFIC (solid line) and IEICO-4F (dashed line) ( Figure 14B), showing the presence of CO i EQE of TLSC with 8DFIC and IEICO-4F as luminophores LSC Sum and average integration J SC Comparison images ( Figure 14C ), and an image showing the photon balance of a TLSC with IEICO-4F ( Figure 14D ).

[0116] Figure 15 The reaction for the synthesis of BODIPY is shown.

[0117] Figures 16A-16D Schematic diagram showing the structure and working principle of a dual-band selectively harvesting transparent luminescent solar concentrator (TLSC), where the UV and NIR components are separated by an air gap that enables total internal reflection within each waveguide and isolates the emission of each luminophore ( Figure 16A ); Molecular structure, normalized absorption and emission spectra of Cs2Mo6I8(CF3CF2COO)6 nanoclusters ( Figure 16B );CO i Molecular structure, normalized absorption and emission spectra of 8DFIC ( Figure 16C ); and the molecular structure, normalized absorption and emission spectra of BODIPY in a polymer matrix ( Figure 16D ).

[0118] Figures 17A-17F Displays only NC, NC+CO i Images of the current density versus voltage (JV) characteristics of TLSCs of 8DFIC and NC+BODIPY, where all scans were measured under AM 1.5G illumination and all TLSCs were edge-mounted with GaAs PV cells ( Figure 17A ); only NC, NC+CO i Average EQE of TLSCs of 8DFIC and NC+BODIPY LSC (λ) spectrum, where the corresponding integrated short-circuit current density ( J SInCt) and Figure 17A The JV characteristic diagram shown in the JV characteristic diagram is extracted SC Good match ( Figure 17B );NC+CO i Absolute position of TLSC of 8DFIC and EQE LSC Spectral relationship ( Figure 17C ); The absolute position of TLSC of NC+BODIPY and EQE L The relationship between SC spectra ( Figure 17D );NC+CO i Normalized position and EQE of TLSC of 8DFICLSC Peak value relationship ( Figure 17E ); and the normalized position and EQE of TLSC of NC+BODIPY LSC Peak value relationship ( Figure 17F ).

[0119] Figures 18A-18B Displays only NC, NC+CO i Transmission spectra (T(λ)) of TLSC of 8DFIC and NC+BODIPY and normalized photopic response (V(λ)) of human eye for comparison ( Figure 18A ) and NC only group, NC+CO in CIELAB color space i 8The TLSCs of DFIC group and NC+BODIPY group (a * ,b * ) coordinates, where in each group, NC concentration (1, 2, 5, 10, and 20 mg / mL) was the only variable ( Figure 18B ). Only CO i 8DFIC and BODIPY TLSCs only (a * ,b * ) is also included as a reference. The insert shows the NC concentration of 10 mg / mL for NC alone, NC + CO i Photos of 8DFIC and NC+BODIPY TLSCs.

[0120] Figures 19A-19B Shown are the NC group only, NC+CO i 8DFIC group, NC+BODIPY group, CO only i Figure 3. Power conversion efficiency (PCE) versus average visible transmittance (AVT) for 8DFIC and BODIPYTLSCs alone. The black line is the Shockley-Queisser (SQ) PCE limit for non-wavelength-selective PVs with partial visible transmittance. The area to the right of the line represents the PCE and AVT combination that can only be achieved with wavelength-selective approaches. Figure 19A ), and images of light utilization efficiency (LUE = PCE × AVT) versus AVT for the NC-only, NC + COi8DFIC, NC + BODIPY, COi8DFIC-only, and BODIPY-only TLSCs, where the black line is the Shockley-Queisser (SQ) LUE limit for non-wavelength-selective PVs with partial visible transmittance, and the area to the right of the line represents the LUE and AVT combination that can achieve the target only by the wavelength-selective approach ( Figure 19B ).

[0121] Figures 20A-20CImages showing the photon balance (including T, R, A, and EQE) of a device comprising only nanoclusters are shown ( Figure 20A ); including nanoclusters and CO i 8DFIC dual-band device ( Figure 20B ); and a dual-band device comprising nanoclusters and BODIPY ( Figure 20C ).

[0122] Figures 21A-21C The photostability study of dual-band TLSCs was shown: under constant illumination, only NC ( Figure 21A ), NC+CO i 8DFIC( Figure 21B ) and NC+BODIPY( Figure 21C )’s absorption spectrum normalized peak, EQE LSC and IQE LSC An image that changes over time.

[0123] Corresponding reference numerals indicate corresponding parts, components and compositions throughout the several views of the drawings. DETAILED DESCRIPTION

[0124] Detailed description

[0125] Exemplary embodiments are provided so that this disclosure will be comprehensive and fully convey the scope to those skilled in the art. Many specific details, such as examples of specific compositions, components, devices, and methods, are set forth to provide a comprehensive understanding of the disclosed embodiments. It will be apparent to those skilled in the art that specific details need not be employed and that the exemplary embodiments may be embodied in many different forms, and neither should be construed as limiting the scope of the disclosure. In some exemplary embodiments, known processes, known device structures, and known technologies are not described in detail.

[0126] The terms used herein are only used to describe specific exemplary embodiments and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may also include plural forms, unless the context clearly indicates otherwise. The terms "comprise", "include", "includes" and "have" are inclusive and therefore specify the presence of specified features, elements, compositions, steps, integers, operations and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. Although the open term "comprising" should be understood as a non-limiting term for describing and claiming the various embodiments described herein, in some aspects, the term may alternatively be understood as a more restrictive and restrictive term, such as "consisting of" or "substantially consisting of". Therefore, for any given embodiment that lists compositions, materials, components, elements, features, integers, operations and / or process steps, the present disclosure also specifically includes an embodiment consisting of or substantially consisting of these listed compositions, materials, components, elements, features, integers, operations and / or process steps. In the case of “consisting of,” the alternative embodiments do not include any additional compositions, materials, components, elements, features, integers, operations and / or process steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations and / or process steps that materially affect the basic and novel characteristics are excluded from the embodiment, but any compositions, materials, components, elements, features, integers, and / or process steps that do not materially affect the basic and novel characteristics may be included in the embodiment.

[0127] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless expressly stated as an order of performance. It should also be understood that additional or alternative steps may be employed unless otherwise stated.

[0128] When a component, element, or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged to, connected to, or coupled to the other component, element, or layer, or intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0129] Although the term first, second, third etc. can be used herein to describe various steps, elements, components, regions, layers and / or parts, unless otherwise indicated, these steps, elements, components, regions, layers and / or parts should not be restricted by these terms. These terms can only be used to distinguish a step, element, component, region, layer or part from another step, element, component, region, layer or part. Unless the context clearly indicates, terms used herein such as "first", "second" and other numerical terms do not mean sequence or order. Therefore, without departing from the teaching of exemplary embodiments, the first step, element, component, region, layer or parts discussed below can be referred to as second step, element, component, region, layer or parts.

[0130] For ease of description, spatial or temporal relative terms may be used herein, such as "before," "after," "inside," "outside," "below," "below," "lower," "above," etc., to describe the relationship of one element or feature to another element or feature, as shown in the figures. Spatially or temporally relative terms are intended to encompass different orientations of a device or system in use or operation in addition to the orientations depicted in the figures.

[0131] Throughout this disclosure, numerical values represent approximate measurements or limits of ranges to encompass minor deviations from a given value, as well as embodiments having approximately the stated value and embodiments having the exact stated value. Except for the working examples provided at the end of the detailed description, all numerical values (e.g., quantities or conditions) of parameters in this specification (including the appended claims) should be understood as being modified by the term "about" in all instances, regardless of whether "about" actually appears before the numerical value. "About" indicates that the numerical value allows for some slight imprecision (approximately or reasonably close to the numerical value by some method). If the imprecision provided by "about" is not understood in this ordinary sense in the art, then "about" as used herein at least indicates the variation that may occur due to ordinary methods of measuring and using these parameters. For example, "about" can include variations of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some aspects, optionally less than or equal to 0.1%.

[0132] Furthermore, disclosure of a range includes disclosure of all values within the entire range and further divided ranges, including endpoints and sub-ranges given for the range.

[0133] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0134] The present technology provides efficient, high-performance TLSCs that provide natural, colorless light. TLSCs include a waveguide operably coupled to a light emitter that selectively absorbs and emits light outside the visible spectrum. These light emitters include non-fullerene acceptors such as thiophene and boron-dipyrromethene (BODIPY). TLSCs exhibit an average visible light transmittance (AVT) greater than or equal to about 50%, a color rendering index (CRI) greater than or equal to about 80 at incidence perpendicular to the waveguide (i.e., 90°), a |b*| value less than 25, and a light utilization efficiency (LUE) greater than or equal to about 1.

[0135] refer to Figure 1A The present technology provides a TLSC 10 comprising a waveguide 12. The waveguide 12 comprises a first surface 14 for receiving light (e.g., incident light) and an opposing second surface 16 for transmitting light. The waveguide 12 also comprises an edge 18. The waveguide 12 comprises a visible transparent material, which may be glass, low iron glass (e.g., from Saint Gobain (Paris, France) or a combination thereof). Low iron glass and Clear glass, and glass from Schott (Mainz, Germany) 33 borosilicate glass), plastics, poly(methyl methacrylate) (PMMA), poly-(ethyl methacrylate) (PEMA), (poly)-butyl methacrylate-co-methyl methacrylate (PBMMA), polyethylene terephthalate (PET), polyimide such as Polyimide films (DuPont, Wilmington), and combinations thereof, are given as non-limiting examples.

[0136] The waveguide 12 is in contact with a light emitter 26 (described in more detail below). Figure 1B A TLSC 10 is shown that receives incident visible (VIS) light 20 and incident near-infrared (NIR) light 22 on a first surface 14 of a waveguide 12. An illuminator 26 absorbs at least a portion of the NIR light 22. However, the illuminator 26 does not substantially absorb the visible light 20 that passes through a second surface 16 of the waveguide 12. The absorbed NIR light 22 excites the illuminator 26, which emits NIR light 24 of a different NIR wavelength, which is guided by the waveguide 12 to the edge 18. Thus, the TLSC collects the NIR light 22, and the waveguide 12 guides the NIR light 24 emitted from the illuminator 26. The emitted NIR light 24 is guided to a photovoltaic PV cell or PV array to generate electricity, as will be discussed in more detail below.

[0137] Figure 2A Shown include Figures 1A-1BFIG. 1 shows a TLSC 10a having a waveguide 12 and luminophores 26. Here, the luminophores 26 are embedded within the waveguide 12. For example, the luminophores 26 are dispersed in a waveguide precursor composition during the manufacturing process. When the waveguide precursor composition is cured or solidified to form the waveguide 12, the luminophores 26 remain embedded in the internal matrix of the waveguide 12.

[0138] Figure 2B A TLSC 10b is shown in which the luminophore 26 is disposed directly on the first surface 14 of the waveguide 12. For example, after the waveguide is formed, a solution containing a solvent and the luminophore 26 can be cast, deposited (e.g., vacuum deposited), pipetted, sprayed, or poured onto the first surface 14. After the solvent is removed, for example, by evaporation, only the luminophore remains on the first surface 14. Although the luminophore 26 is shown as being disposed directly on the first surface 14, it should be understood that the luminophore 26 can alternatively be disposed directly on the second surface 16 or on both the first surface 14 and the second surface 16.

[0139] Figure 2C A TLSC 10c is shown that includes a film 28 that includes a light emitter 26, wherein the film 28 is disposed directly on the first surface 14 of the waveguide 12 (which is located at the bottom of the waveguide 12). Figure 2C 14). The film 28 can be formed on the waveguide 12, or the film 28 can be formed separately and then disposed on the first surface 14 of the waveguide 12. The film includes visible transparent materials such as polymethyl methacrylate, poly(n-butyl acrylate) / poly(methyl methacrylate-co-methacrylic acid), polycarbonate, polydimethylsiloxane, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, SiO2, mounting media such as Eukitt and Shandon, and combinations thereof, as non-limiting examples. Although the film 28 is shown as being disposed directly on the first surface 14, it should be understood that the film 28 can alternatively be disposed directly on the second surface 16 or on both the first surface 14 and the second surface 16. In some aspects, the film 28 is coupled to the waveguide by an adhesive, which can be an adhesive having a low refractive index.

[0140] As described above, the luminophore 26 collects (i.e., absorbs) light having a wavelength in at least one of the NIR and IR regions of the solar spectrum. As used herein, UV light has a wavelength of about 300 nm to about 450 nm, VIS light has a wavelength of about 450 nm to about 650 nm, NIR light has a wavelength of about 650 nm to about 1500 nm, and IR light has a wavelength of about 1500 nm to about 1 mm. The luminophore 26 has its strongest maximum absorbance at a wavelength greater than or equal to about 650 nm. Many luminophores have multiple maximum absorbances, possibly in different regions of the spectrum. Thus, the "strongest maximum absorbance" is the absorbance maximum with the largest peak. Thus, the luminophore 26 has its strongest maximum absorbance in the NIR region of the spectrum or in the infrared (IR) region of the spectrum. The luminophore 26 has its strongest peak emission of light at a wavelength greater than or equal to about 650 nm. Similarly, many luminophores have multiple emission maxima, possibly in different regions of the spectrum. Thus, the "strongest peak emission" is the emission maximum with the largest peak. The luminophore 26 has the strongest peak emission in the NIR region of the spectrum or in the IR region of the spectrum.

[0141] In some aspects, the emitter 26 has a strongest maximum absorbance at greater than or equal to about 650 nm in the NIR and IR regions of the spectrum, and absorbs less than or equal to about 50%, less than or equal to about 30%, less than or equal to about 20%, less than or equal to about 10%, or less than or equal to about 5% of the total light incident on the emitter 26 at wavelengths in the visible region of the spectrum. In other words, less than or equal to about 50%, less than or equal to about 30%, less than or equal to about 20%, less than or equal to about 10%, or less than or equal to about 5% of the total VIS incident light contacting the emitter is absorbed by the emitter 26. Conversely, greater than or equal to about 50%, greater than or equal to about 70%, greater than or equal to about 80%, greater than or equal to about 90%, or greater than or equal to about 95% of the total visible light contacting the waveguide 12 and the emitter 26 is completely transmitted through the waveguide 12 without being scattered. Thus, TLSC 10 (as well as TLSCs 10a, 10b, and 10c) is visibly transparent and substantially free of haze. As used herein, the term "substantially free of haze" means that the device has a haze of less than or equal to about 20%, as discussed in more detail below. As used herein, the terms "transparent" or "visibly transparent" mean an average visible light transmittance (AVT) greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 75%, greater than or equal to about 80%, or greater than or equal to about 90%. The terms "opaque" or "apparently opaque" refer to a device having an average visible transparency weighted by the eye's photopic response to specular transmission of 10% or less. A device having an AVT between 10% and 50% (weighted by the eye's photopic response) is "translucent." Thus, the TLSCs 10, 10a, 10b, 10c with the luminophore 26 are visibly transparent, have the strongest peak absorption in the NIR / IR and have the strongest peak emission in the NIR / IR.

[0142] The luminophore 26 has an optical integral (OI) of less than or equal to about 50, less than or equal to about 20, less than or equal to about 10, or less than or equal to about 5. The OI quantifies the reabsorption characteristics of the luminophore as:

[0143]

[0144] where A(λ) is the single-pass absolute absorption spectrum of the emitter / host composite film (A(λ)–1–R(λ)–T((λ)) and PL * (λ)dλ is the normalized emission spectrum of the emitter in the host material. The OI depends on the thickness of the emitter layer and the degree of overlap between the absorption and emission spectra in the host material (not the solution). Therefore, a decrease in OI corresponds to a decrease in the overlap between the absorption and emission spectra. By reducing the overlap between the absorption and emission spectra, efficiency losses due to reabsorption are reduced.

[0145] The luminophore 26 has a Stokes shift of greater than or equal to about 10 nm or greater than or equal to about 30 nm, including about 10 nm, about 20 nm, about 30 nm, about 40 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, about 150 nm, or more.

[0146] In some aspects of the present technology, the luminophore 26 is a non-fullerene acceptor (electron acceptor), such as thiophene, polythiophene, or a combination thereof. Non-limiting examples of thiophenes and polythiophenes include 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2",3"":4",5"']thieno[2",3"':4",5"]pyrano[2",3":4',5']thieno[2',3':4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i 8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-s-indene and [1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), their derivatives (each of which has a molecular weight change of no more than about 50% and retains each thiophene skeleton), and combinations thereof.

[0147] In other aspects, the emitter 26 is boron-dipyrromethene (BODIPY) having the following structure.

[0148]

[0149] The luminophore 26 may also be a BODIPY derivative that retains the following BODIPY backbone, such as BOD-66, KeioFlours (KFL), oligothienyl-BODIPY, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, "zig-zag" edge-fused BODIPY, aza-BODIPY, [a]-fused BODIPY, [b]-fused BODIPY, and combinations thereof, as non-limiting examples. These compounds may optionally be used in combination with BODIPY.

[0150]

[0151] The luminophore 26 can be any combination of thiophene, polythiophene, and BODIPY. For example, the TLSC 10 can include a first luminophore and a second luminophore, wherein the first luminophore is thiophene or polythiophene, and the second luminophore is BODIPY.

[0152] In some aspects, the luminophore 26 is a luminescent nanocluster having a strongest maximum absorbance of less than or equal to about 450 nm in the UV region of the spectrum, and absorbs less than or equal to about 50%, less than or equal to about 30%, less than or equal to about 20%, less than or equal to about 10%, greater than or equal to about 10%, or less than or equal to about 5% of the total light incident on the luminophore 26 at wavelengths in the visible region of the spectrum. In other words, less than or equal to about 50%, less than or equal to about 30%, less than or equal to about 20%, less than or equal to about 10%, or less than or equal to about 5% of the total VIS incident light contacting the luminophore 26 is absorbed by the luminophore 26. Conversely, greater than or equal to about 50%, greater than or equal to about 70%, greater than or equal to about 80%, greater than or equal to about 90%, or greater than or equal to about 95% of the total visible light contacting the waveguide 12 and the luminophore 26 is completely transmitted through the waveguide 12. The luminophore 26 has its strongest peak emission in the near-infrared region or the infrared region of the spectrum. Thus, the TLSC 10, 10a, 10b, 10c having luminescent nanoclusters is visibly transparent and substantially free of haze. As used herein, the term "substantially free of haze" means that the device has a haze of less than or equal to about 20%, as discussed in more detail below.

[0153] The luminescent nanoclusters may be hexanuclear clusters, octahedral clusters, tetrahedral clusters, Chevral clusters, edge-capped halide clusters, metal clusters, or chalcogenide clusters. The hexanuclear clusters may include phosphorescent metal halide nanoclusters or phosphorescent metal halide nanocluster salts. As a non-limiting example, the metal halide or metal halide salt may be M6X 12 、M6X 12 nR, A2M6X 14 、A2M6X 14 nR, EM6X 14 EM6X 14 ·nR, M6X8L6, A2M6X8L6, M6X 14 、M6X 14 nR, A4M6X 18 , or A4M6X 18 nR, where M represents a metal, X represents a halogen, A and E represent terminal 1+ and 2+ cations, respectively, R represents a primary ligand, L represents a secondary ligand, such as propionate or pentafluoropropionate, and n is a value between 0 and M+X. M is Mo, W, Cr, Mn, Tc, Re, Cu, Ti, V, Ta, Nb, Sn, Zn, Zr, or Ga; X is F, Cl, Br, I, At, or a mixture thereof; A is H + 、H3O + , K + 、Na + 、Li + , Rb + 、Cu + 、Cs + , ammonium, butylammonium, tetrabutylammonium (TBA) or NR'4 + , wherein R' is independently selected from alkyl or aryl, wherein R' is optionally substituted by halogen, nitro, cyano, hydroxy, hydroxyalkyl, haloalkyl, haloalkoxy, amino, azido, carboxyl, carbamoyl, thiol, sulfamoyl, C 1-10 Alkyl, C 2-10 Alkenyl, C 2-10 Alkynyl, C 1-10 Alkoxy, C 1-10 Alkoxyalkyl, C 1-10 Alkanoyl, C 1-10 Alkanoyloxy, N-(C 1-10 alkyl)amino, N,N-(C 1-10 Alkyl)2amino, C 1-10 Alkylamino, N-(C 1-10 alkyl)carbamoyl, N,N-(C 1-10 alkyl)2-carbamoyl, C 1-10 Alkyl-S(O)a (where a is 0, 1 or 2), C 1-10 Alkoxycarbonyl, N-(C 1-10 alkyl)sulfamoyl, N,N-(C 1-10 alkyl)2sulfamoyl, H2NS(O)2NH-, N-(C 1-10 alkyl)NHS(O)2NH-、N,N-(C 1-10 alkyl)2NS(O)2NH-, aryl, aryloxy, arylthio, heteroaryl, heteroaryloxy, cycloalkyl, cycloalkoxy, heterocyclyl, heterocyclyl (C=O)-, heterocyclyloxy and heterocyclylthio, wherein these choices are non-limiting; L is F, Cl, Br, I, At, S, propionate, pentafluoropropionate or a mixture thereof, and E is Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Cu 2+ 、Ni 2+ 、Ti 2+ 、Ba 2+ or a mixture thereof; R is H2O, CH3CN or any other solvate.

[0154] Metal halide clusters, such as phosphorescent metal(II) halide clusters, can be modified from parent salt compounds via ligand exchange reactions. The parent ion is typically synthesized by reducing M(V)X5 or obtained directly as M(II)X2. For molybdenum-based clusters, the parent compound is purified by conversion to the HCl salt, which is then returned to M(II)X2 or M(II)X by vacuum heat treatment. 12 . Ligand exchange can be carried out in a Soxhlet extractor or directly reacted in acidic solution in the presence of free cations to form various complexes or salts, respectively. The properties of the selected range of metal halide complexes (hydrates and salts) synthesized here show quantum yields ranging from about 1% to greater than about 70%. Many amine and thiol based ligands can be substituted around the terminal halide by coordination of thiolates and amines. M, X and L are in MX2.L2, AMX2.L2, M6X 12 .L2, A2M6X 14 and A2M6X 14 L2 is different and includes M = W, Mo, X = Cl, Br, I, and L = Cl, CH3CN, benzenethiol, ethanethiol, H2O (hydrate), HCl, acetonitrile (CAN), and A = K, Na, tetrabutylammonium (TBA) and other ammonium salts. In addition, amines and ammonium salts can be easily anchored to the polymer chain backbone to enhance particle separation and increase quantum yield. Exemplary phosphorescent nanoclusters include K2Mo6Cl 14、TBA2Mo6Cl 14 、(H3O)2Mo6Cl 14 and their combinations.

[0155] The TLSC 10 of FIG. 1 also includes photovoltaic (PV) components, such as PV cells or a PV array. Figure 3A and 3B Shown with Figure 1A and Figure 1B The TLSC 10 in FIG. 1 has the same components as the TLSCs 10 ′, 10 ′*. However, the solar concentrator 10 ′ includes a PV cell 30 disposed on one of the edges 18 of the waveguide 12, and the TLSC 10 ′* includes a PV cell 30 disposed on the first surface 14 of the waveguide 12, and the PV cell 30 is optionally disposed on the edge 18 and / or the second surface 16, such that the PV cell 30 is operably coupled to the waveguide 12. By “operably coupled” is meant that NIR or IR radiation emitted from the luminaire 26 within the waveguide 12 can be transferred to the PV cell 30. In various aspects, Figure 3A The TLSC 10' includes a PV cell 30 on at least one edge 18 of a waveguide 12. Figure 3B In the embodiment of the present invention, the PV cell 30 is located at or near an edge 18 on the first and / or second surface 14, 16 of the waveguide 12, which edge 18 may be, for example, rectangular, curved, or chamfered. By "at or near edge 18" is meant that the PV cell 30 is adjacent to the edge 18, or is within about 10 cm, about 5 cm, or about 2.5 cm of the edge 18. In aspects where the PV cell 30 is disposed on a surface 14, 16 of the waveguide 12, the waveguide surface 14, 16 may be roughened at the location of the PV cell 30, or the PV cell 30 may be embedded in the waveguide 12 to ensure that the PV cell 30 is operably coupled to the waveguide 12 by reducing total internal reflection at the PV-waveguide interface.

[0156] Figure 3C and 3D Shown with Figure 1A and 1B The solar concentrator 10 has the same components as the TLSCs 10'**, 10'***. However, Figure 3C and 3D The TLSCs 10'**, 10'*** include at least one wavelength dependent reflector 32 and at least one PV cell 30. More specifically, Figure 3C In FIG, the TLSC 10 ′** includes a PV cell 30 located at or near the edge 18 on the first surface 14 of the waveguide 12 and a wavelength-dependent reflector 32 on the edge 18. An optional second wavelength-dependent reflector 32 is provided at or near the edge 18 on the second surface 16 of the waveguide 12. Figure 3DIn the embodiment, the TLSC 10'*** includes a PV cell 30 disposed at or near the edge 18 on the second surface 14 of the waveguide 12 and a wavelength dependent reflector 32 disposed on the edge 18. Figure 4 A description of wavelength-dependent reflectors is provided in more detail.

[0157] Figure 3E and 3F Shown with Figure 1A and Figure 1B The solar concentrator 10 in FIG. 1 is identical to the components of the TLSC 10 ″, 10 ″′. However, the TLSC 10 ″, 10 ″′ has a segmented PV array 34 operatively coupled to the waveguide 12. Figure 3E In FIG. 1 , a PV array 34 is disposed on the surface 14 of the waveguide 12. Figure 3F As shown, a PV array 34 is disposed within a central region 36 of the waveguide 12, for example within the bulk of the matrix within the waveguide 12. The PV array 34 can be provided as a coating or spray-on on the waveguide 12, or by laminating a dye sheet as a layer between alternating stacks that together form the waveguide 12. While the PV array 34 may not be visibly transparent, its size is sufficiently small that the PV array 34 does not substantially affect the transparency characteristics of the solar concentrator 10. For example, in various embodiments, the PV array 34 occupies less than or equal to about 20%, less than or equal to about 15%, less than or equal to about 10%, less than or equal to about 5%, or less than or equal to about 2.5% of the waveguide 12. In other words, the PV array 34 blocks less than or equal to about 20%, less than or equal to about 15%, less than or equal to about 10%, less than or equal to about 5%, or less than or equal to about 2.5% of the light that contacts the solar concentrator 10. In some embodiments, the PV array 34 may be slightly visible to a human observer as a thin line or dot, or the PV array 34 may be microscopic and not visible to a human observer.

[0158] In various aspects, the PV array 22 is a mesh comprising wires, microwires, nanowires, ribbons, strips, spheres, dots, combinations thereof, etc., arranged within or placed on the surface 24 of the waveguide 16 ( FIG. 2F ). More than one PV array 22 may be used to reduce heat loss. Figure 2B The PV cells 18 of FIG. 2F and FIG. 2G , and the PV array 22 of FIG. 2F and FIG. 2G , may comprise any material known in the art. Non-limiting examples of solar array and solar cell materials include germanium (Ge); amorphous germanium (a-Ge); gallium (Ga); gallium arsenide (GaAs); gallium nitride (GaN), gallium indium nitride (INN), and the like. x Ga 1-xN, where 0 < x < 1), silicon (Si); amorphous silicon (a-Si); silicon germanium (SiGe); amorphous silicon germanium (a-SiGe); gallium indium phosphide (GaInP); copper indium selenide, copper indium sulfide or a combination thereof (CIS); copper indium gallium selenide, copper indium gallium sulfide or a combination thereof (CIGS); cadmium telluride (CdTe); perovskite (PV), such as CH3NH3PbI3, CH3NH3PbCl3 and CH3NH3PbBr3; and combinations thereof.

[0159] In some aspects, regarding Figure 3E and Figure 3F the PV arrays 34 shown in TLSCs 10” and 10”’ are connected in series and may include adducts, such as spheres or dots. For example, the PV array 34 can include a silicon sphere solar array connected by fine wire electrical connections. In one embodiment, the PV array 34 includes spheres connected together to form a mesh. Advantageously, using a spherical or polyhedral PV array 34 further improves system efficiency because each cell can capture direct and indirect sunlight at multiple angles. The PV array 34 can be located at different positions within the waveguide 12, at or near the surfaces 14, 16, or the PV array 34 can have a thickness approximately the same as the total thickness of the waveguide 12. In some aspects, the TLSCs 10” and 10”’ can include multiple PV arrays 34 located at different positions within the waveguide 12.

[0160] By positioning the segmented PV array 34 at the first or second surface 14, 16 of the waveguide 12, the emitted light can be captured before optical losses due to dye reabsorption. Alternatively, the PV array 34 can be embedded within the waveguide 12. This reabsorption loss is particularly beneficial for fluorescent materials with a small Stokes shift. Depending on the position of the PV array 34 within the waveguide 12, the emitter 26 can be embedded within or juxtaposed to the PV array 34. Additionally, by positioning the PV array 34 at the first or second surface 14, 16 of the waveguide 12, a portion of the forward-emitted light can be captured, which further reduces optical losses and improves the efficiency of the spatially segmented PV array 34 by utilizing more of the NIR light between cells.

[0161] As Figure 4As shown, the TLSC 50 can include a first wavelength-dependent reflector 52. The first wavelength-dependent reflector 52 can have a NIR light reflectivity corresponding only to the emission spectrum of the luminophore, as shown in graph 80. Thus, the first wavelength-dependent reflector 52 is transparent to visible light 54 but reflects NIR light 56 within the emission range shown in graph 80. The first wavelength-dependent reflector 52 can be functionally coupled to a first surface 58 of the TLSC 50, which includes a luminophore as described above. Alternatively, the first wavelength-dependent reflector 52 can be functionally coupled to a second surface 60 of the TLSC 50, or to both surfaces 58, 60. In other aspects, the luminophore is located on the second surface 60 or embedded within a waveguide.

[0162] With further reference to FIG3 , the TLSC 50 can include a second wavelength-dependent reflector 62. The second wavelength-dependent reflector 62 can have a NIR light reflectivity corresponding to the absorption and emission spectra of the modified luminophore shown in graph 90. The second wavelength-dependent reflector 62 is transparent to visible light 54 but reflects NIR light 56 within the emission range shown in graph 90. The second wavelength-dependent reflector 62 can be functionally coupled to the first surface 58 of the TLSC 50, the second surface 60 of the TLSC 50, or both surfaces 58, 60. In one embodiment, the first wavelength-dependent reflector 52 is functionally coupled to the first surface 58 of the TLSC 50, and the second wavelength-dependent reflector 62 is functionally coupled to the second surface 60 of the TLSC 50. As described above, the photovoltaic array can be located on the first surface 58, the second surface 60, or within the waveguide. In various embodiments, the TLSC 50 includes a plurality of solar arrays located on either the first surface 58, the second surface 60, or within the waveguide between the first and second surfaces 58, 60. In some other embodiments, the TLSC 50 includes solar cells located at edges of the TLSC 50 adjacent to the first and second surfaces 58 , 60 .

[0163] Incorporating visible transparent selective NIR wavelength dependent reflectors 52, 62 in transparent photovoltaics (TPVs) can significantly increase power conversion efficiency by 50-100%. Similarly, incorporating these reflectors 52, 62 increases optical efficiency by more than about 20% at low panel sizes while reducing the amount of modified luminophore required for a given optical density by about half. 2The reflectors 52, 62 help mitigate any surface and bulk scattering imperfections that may reduce the efficiency of the system, given the size of the solar collector. The reflectors 52, 62 may be coatings that improve collector absorption and increase waveguiding. Furthermore, these coatings are very similar to the low-emissivity coatings already in common use and may supplement or replace much of their heat dissipation function. Alternating layer combinations of TiO2, SiO2, and Al2O3 may be grown by electron beam evaporation, pulsed laser deposition, plasma enhanced sputtering, thermal deposition, chemical vapor deposition, or solution deposition to optimize overall color impact and performance. It will be appreciated that the above descriptions of Figure 4 The discussion applies to Figures 1A-1B , TLSCs in 2A-2B and 3A-3F.

[0164] refer to Figure 5A The present technology also provides a transparent dual-band device 100. The dual-band device 100 includes the above reference Figures 1A-1B , 2A-2B, 3A-3F and Figure 4 All arrangements of waveguides 12 discussed above are discussed. However, as described above, the luminophore 26 has a maximum absorbance and a peak emission at approximately 650 nm or greater, and a quantum yield of approximately 15% or greater, approximately 20% or greater, or approximately 25% or greater. The luminophore 26 is not a UV-harvesting luminescent nanocluster as described above. Therefore, the luminophore is a thiophene, a polythiophene, a BODIPY, a porphyrin, a phthalocyanine, or a combination thereof. The transparent dual-band device 100 also includes a second luminophore 102 and a second waveguide 104 that guides light emitted from the second luminophore 102. As described above, the second luminophore 102 is a light emitter having a maximum absorbance at approximately 450 nm or less and a peak emission at approximately 650 nm or greater. As a non-limiting example, the second luminophore 102 can be at least one of the luminescent nanoclusters described above. Additionally, the second light emitter has a quantum yield (QY) of greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 40%, or greater than or equal to about 50%.

[0165] The second waveguide 104 has a third surface 106 and an opposing fourth surface 108 and an edge 110 (at Figure 5AOnly one of the four edges 110 is visible). The third surface 106 receives incident light and the fourth surface 108 transmits light. The waveguides 12, 104 are arranged adjacent to each other such that the first surface 14 of the waveguide 12 receives light transmitted through the fourth surface 108 of the second waveguide 104. In addition, the second waveguide 104 is not in direct physical contact with the waveguide 12. Instead, the waveguides 12, 104 are arranged in a manner that defines a gap (or spacing) 112 between the waveguide 12 and the second waveguide 104. The gap 112 ensures that the emitted light guided in each waveguide 12, 104 is not transferred to the opposing waveguide 12, 104. For example, the gap 112 prevents the luminophore 26 from possibly absorbing NIR light emitted from the second luminophore 102. The width of the gap 112, i.e., the distance between the first surface 14 of the waveguide 12 and the fourth surface 108 of the second waveguide, is W G , which is greater than or equal to about 1 nm, to less than or equal to about 10 mm, or even wider. Exemplary width W G Including about 10nm, about 100nm, about 500nm, about 1μm, about 1μm, about 1μm, about 1μm, about 100μm, about 250μm, about 500μm, about 750μm, about 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm and 10mm.

[0166] The transparent dual-band device 100 also includes at least one PV cell 114. Each PV cell 114 is coupled to a corresponding edge 18, 110 of the waveguides 12, 104. In other words, a single, unitary PV cell 114 is coupled to the edge 18 of the waveguide 12 and the edge 110 of the second waveguide 104. Thus, the transparent dual-band device 100 is a single-cell device (as opposed to a dual-cell, multi-cell, or multi-function device, each waveguide having a separate PV cell). In some aspects, a light emitter having the strongest maximum absorbance in the UV and the strongest peak emission in the NIR and / or IR is used with a second light emitter having the strongest maximum absorbance in the UV and the strongest peak emission in the UV. In other aspects, a light emitter having the strongest maximum absorbance in the UV and the strongest peak emission in the NIR and / or IR is used with a second light emitter having the strongest maximum absorbance in the NIR and the strongest peak emission in the NIR and / or IR, where the strongest peak emission of the light emitter is different from the strongest maximum absorbance and the strongest peak emission of the second light emitter. Through these aspects, the same PV cell can be coupled to both waveguides or a different PV cell can be coupled to each waveguide, where each PV cell has a different bandgap close to the emission edge of the UV absorber / emitter and NIR absorber / emitter to reduce thermalization losses.

[0167] Figure 5B yes Figure 5A5B / 5C. More specifically, Figure 5B Transparent dual-band device 100a is shown with gap 112a filled with air. Thus, gap 112a is an air gap or layer containing air. Here, the last PV cell 114 can maintain the device architecture. However, transparent dual-band device 100a optionally includes a spacer 116 separating waveguide 12 from second waveguide 104.

[0168] Figure 5C yes Figure 5A 5B / 5C. More specifically, Figure 5C A transparent dual-band device 100b is shown, wherein gap 112b is a layer comprising a visually transparent material. The visually transparent material has a refractive index (n) of less than or equal to approximately 1.45 or less than or equal to approximately 1.3. Thus, the refractive index (n) ranges from greater than or equal to approximately 1 to less than or equal to approximately 1.45, or from greater than or equal to approximately 1 to less than or equal to approximately 1.3. The refractive index (n) can be approximately 1, approximately 1.05, approximately 1.1, approximately 1.15, approximately 1.2, approximately 1.25, approximately 1.3, approximately 1.35, approximately 1.4, or approximately 1.45.

[0169] As described above, all devices described herein have an AVT greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 75%, greater than or equal to about 80%, or greater than or equal to about 90%. Exemplary AVTs exhibited by devices of the present technology include about 50%, about 55%, about 60%, about 65%, about 70%, about 80%, about 85%, about 90%, and about 95%.

[0170] All devices described herein have a color rendering index (CRI) greater than or equal to about 80, greater than or equal to about 85, or greater than or equal to about 90. Exemplary CRIs exhibited by devices of the present technology include about 80, about 85, about 90, and about 95. The transmittance (AVT) and clarity values provided herein are at incidence normal to the waveguide (i.e., 90°).

[0171] All devices described herein have an L as defined by the International Commission on Illumination (CIE) * a * b * Color space, namely CIELAB color space, which is essentially white. More specifically, these devices exhibit |a * | and |b * | value is less than or equal to about 25, less than or equal to about 20, less than or equal to about 15, less than or equal to about 10, and less than or equal to about 5, and L *A value greater than or equal to about 10, greater than or equal to about 25, greater than or equal to about 50, greater than or equal to about 75, or greater than or equal to about 95, including L * The values of sqrt(|a) are about 100, about 95, about 90, about 85, about 80, about 75, about 70, about 65, about 60, about 55, about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, and about 10. More specifically, these devices exhibit a sqrt(|a) of less than or equal to about 25, less than or equal to about 20, less than or equal to about 15, less than or equal to about 10, or less than or equal to about 5. * | 2 +|b * | 2 )value.

[0172] All devices described herein have a haze or transmittance haze, which is defined as diffuse transmittance (i.e., the amount of light that is scattered in the device but still transmitted through) divided by total transmittance (i.e., the total amount of light that passes through, whether scattered or not), less than or equal to about 20%, less than or equal to about 10%, less than or equal to about 5%, less than or equal to about 2%, or less than or equal to about 1%, including haze of about 20%, about 18%, about 16%, about 14%, about 12%, about 10%, about 8%, about 6%, about 4%, about 2%, about 1% and less. Thus, these devices are substantially free of haze.

[0173] All devices described herein have a power conversion efficiency (PCE) greater than or equal to about 1%, greater than or equal to 1.5%, greater than or equal to about 2%, or greater than or equal to about 3%.

[0174] Light utilization efficiency (LUE) is the product of PCE and AVT. For example, if a device has a PCE of 2.0% and an AVT of 50%, the LUE will be 2.0% * 50% = 1.0% or simply 1.0. A LUE of 0 means the device is not transparent. All devices described herein have a LUE greater than or equal to about 0.9. For example, a TLSC comprising thiophene or polythiophene as the only luminophore has a LUE of about 0.92. A TLSC comprising BODIPY as the only luminophore has a LUE of about 1.26. A TLSC comprising luminescent nanoclusters as the only luminophore has LUEs of 1.01, 1.59, and 1.84. A transparent dual-band device having a first waveguide comprising luminescent nanoclusters and a second waveguide comprising BODIPY (in the order in which the waveguides contact the incident light) has LUEs of about 1.3, about 1.49, about 1.92, about 2.36, and about 2.6. A first waveguide comprising light-emitting nanoclusters and a waveguide comprising CO iThe transparent dual-band device of the second waveguide of the 8DFIC (in the order in which the waveguides contact the incident light) has a LUE of about 1.19, about 1.56, about 1.89, and about 2.12. Thus, the present technology provides TLSCs and transparent dual-band devices with a LUE greater than or equal to about 0.9, greater than or equal to about 0.95, greater than or equal to about 1, greater than or equal to about 1.5, or greater than or equal to about 2, including LUEs of about 0.9, about 0.95, about 1, about 1.05, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, and higher.

[0175] Optimizing PCEs to achieve the best possible aesthetic effect leads to PCE / (sqrt(a * ^2+b * ^2)) is greater than or equal to about 0.05, greater than or equal to about 0.08, greater than or equal to about 0.1, greater than or equal to about 0.13.

[0176] The TLSCs described above can be incorporated into buildings, vehicles, and devices to generate energy. Accordingly, the present technology provides buildings, vehicles, and devices that include the TLSCs described above.

[0177]

[0014] Embodiments of the present technology are further illustrated by the following non-limiting examples.

[0178] Example 1

[0179] Transparent Luminescent Solar Concentrators (TLSCs) selectively collect ultraviolet (UV) and near-infrared (NIR) light. The absence of electrodes, busbars, and collector grids over the solar collection area allows these devices to achieve the highest levels of transparency and aesthetics. In this example, we incorporate non-fullerene acceptors, such as CO i 8DFIC was introduced into TLSCs as a luminophore. i Effect of 8DFIC concentration on power conversion efficiency (PCE), aesthetic quality and scalability. After device optimization, CO i The PCE of 8DFIC TLSCs exceeds 1.2%, while the average visible transmittance (AVT) exceeds 74% and the color rendering index (CRI) exceeds 80. This example reports the highest TLSC device efficiency at the highest reported visible transparency.

[0180] introduce

[0181] Visible transparent photovoltaics (TPVs) can selectively collect ultraviolet (UV), near infrared (NIR) or visible light (VIS) that partially and unpreferably passes through the solar spectrum. TPVs can therefore effectively meet on-site energy needs with minimal impact on the functional and aesthetic qualities of the underlying surfaces, thereby improving overall energy efficiency. The technology can be applied to small-area applications, including (autonomous) mobile electronic devices, displays, and electric vehicles, with a huge potential market due to increasing production. In addition to these small-area applications, as TPVs become more scalable, they can be integrated into building facades, converting new and existing infrastructure into a source of power generation and significantly reducing electrical losses in transmission.

[0182] Transparent Luminescent Solar Concentrators (TLSCs) are a key TPV technology that optically shifts solar energy conversion via photoluminescence (PL) and transmits it optically (via total internal reflection) to edge-mounted PV cells ( Figure 6A ). Since there are no electrodes, busbars, and collection grids on the solar energy collection area, the device structure is greatly simplified, which enables LSC / TLSC devices to achieve the highest level of transparency and aesthetics. In the past decade, quantum dots, nanoclusters, and rare earth ion complexes have been widely studied as luminophores in LSC / TLSC systems. These works mainly focus on (1) improving quantum yield (QY), (2) modulation of absorption and emission spectra to minimize reabsorption losses, and (3) enhancing light absorption by matching the absorption spectrum of the luminophore with the peak of the incident solar spectrum. However, if high aesthetic quality and transparency are the goals, the continuous band absorption characteristics of these luminophores limit their absorption cutoff wavelength to about 435 nm. Band gaps exceeding 440 nm will lead to a rapid decrease in average visible light transmittance (AVT) and color rendering index (CRI). Wavelength selective absorbers can be used to collect only UV or NIR. CRI and AVT reach their maximum values when the selective absorption red shift exceeds 675 nm. Therefore, NIR photons between 675 nm and the absorption cutoff of edge-mounted photovoltaic cells can be used for power generation, a range that coincides with the peak of the incident AM 1.5G photon flux. Furthermore, even with extreme absorption in the red NIR below 675 nm, the resulting blue / green hues are generally more visually acceptable than yellow / red hues, providing more design freedom for NIR-selective harvesting emitters.

[0183] Light absorption in organic and molecular semiconductors originates from transitions from the ground state to excited molecular orbitals (e.g., S0→S1, S0→S2). The gap between the excited molecular orbitals (S1 and S2) results in a discontinuity in the density of states, which allows photon transmission. The molecular structure can be designed so that this gap overlaps with the visible spectrum, resulting in visible transparency. In general, organic dyes can be designed to selectively collect NIR photons, which is generally not possible with conventional semiconductors. However, organic light emitters typically have large self-absorption (large overlap between absorption and PL), narrow absorption peaks, and relatively low QY in the NIR. Recently, CO i 8DFIC (also known as O6T-4F, Figure 6B ) have been developed as non-fullerene acceptors in organic photovoltaics with unprecedented performance. In this example, non-fullerene acceptors (including CO i 8DFIC) was introduced as a luminescent emitter into NIR selective harvesting TLSCs, where the power conversion efficiency (PCE) was more than doubled to 1.24%, which is the best NIR selective harvesting TLSC to date and the highest PCE reported with an AVT of over 70%. Due to the high visible transparency of the wavelength selective harvesting, the light utilization efficiency (LUE=PCE×AVT) is also comparable to the highest LUE of quantum dot-based LSCs. Using this material theme, efficiencies close to 5% and similar levels of AVT can be achieved simply by increasing the QY from about 25% to close to 100%, and efficiencies of over 10% can be achieved by additionally increasing solar energy harvesting near the visible spectrum.

[0184] experiment

[0185] CO i 8DFIC synthesis.

[0186] NMR spectra were obtained on a 500 MHz Varian NMR spectrometer using the residual 1H peak from the deuterated solvent as a reference. Column chromatography was performed using 35-75 μm silica gel. Analytical TLC was performed using pre-coated 0.25 mm thick silica gel 60 F254 plates, visualized using ultraviolet light. Compounds A and D were purchased from ChemShuttle Co.

[0187] refer to Figure 7A , CO iThe synthesis of 8DFIC closely follows known procedures, with minor changes to some of the steps as described below. The synthesis begins with bromide A and provides bromoisomeric esters B and C in a two-step process in a ratio of ~2:1. Column chromatography was not effective in separating the desired isomer B, so crystallization was employed. Recrystallization of the B / C mixture was initiated by dissolving the material in pure DCM at room temperature. Slow addition of Et2O resulted in crystal formation. When the final ratio of Et2O:DCM reached 3:1, the addition of Et2O was terminated. The solution was kept at room temperature overnight, and the crystals were filtered using a Buchner funnel and washed with cold Et2O. The isolated crystals resulted in a significant increase in the purity of the desired isomer (10:1 B:C) for subsequent transformations. Subsequent steps were performed until CO was obtained. i 8-CHO. For the last reaction, it was found that extending the reaction time would lead to a decrease in yield. i The reaction between 8-CHO and D was terminated within 3 hours, resulting in the isolation of the target molecule with a yield of 91%. The molecular structure of thiophene ITIC is shown in Figure 2. Figure 7B shown.

[0188] Module manufacturing.

[0189] CO i DFIC powder was aggregated and dissolved in dichloromethane (5 min ultrasonic treatment) to prepare a solution of target concentration. -1 TLSC, 150mgL -1 The dichloromethane solution was uniformly mixed with (poly)-butyl methacrylate-co-methyl methacrylate (PBMMA) (Sigma-Aldrich) in a volume ratio of 1:1. The composite mixture was drop-cast onto a 5.08 cm × 5.08 cm × 0.635 cm glass plate (for JV characterization) and dried in a glove box filled with nitrogen (O2, H2O <1 ppm) for 3 hours to obtain a layer thickness of approximately 0.5 mm. The same layer structure was applied to 2.54 cm × 2.54 cm × 0.1 cm (for PL and QY measurements). For photovoltaic measurements, single-crystal solar cells (Vikocell Solar) were laser-cut into 5.08 cm × 0.635 cm strips for JV and corresponding EQE LSC The 10.16 cm × 0.635 cm strips were used for position-dependent EQE measurements. Edge-mounted GaAs PVs (Alta Devices) were used as received. For JV measurements, two PV strips were mounted on orthogonal edges using index matching gel (Thorlabs) to connect the PV strips to the waveguide edges and connect them in parallel. The remaining two edges were painted black to block light and internal reflections of light. For EQE LSC To measure, attach a PV strip to one edge of the waveguide and paint the other three edges black.

[0190] Optical properties.

[0191] The specular transmittance (T(λ)) of the solution and TLSC device was measured using a dual-beam Lambda 800 UV / VIS spectrometer in transmission mode. No reference sample was placed on the reference beam side for the transmittance measurements of the solid film TLSC. The reflectance (R(λ)) of the TLSCs was also measured using a Lambda 800 UV / VIS spectrometer with the specular accessory mounted on the sample beam side. The absorption spectrum was obtained using the following equation: A(λ) = 1 - T(λ) - R(λ). CO was measured by excitation at 650 nm using a PTI QuantaMaster40 fluorescence spectrophotometer. i PL of 8DFIC in chlorobenzene solution and polymer matrix. Photoluminescence quantum yield was measured using a Hamamatsu Quantaurus fluorimeter with an excitation range of 650–750 nm in scan mode (10 nm per scan step). Reported QY values are the average of 11 measurements.

[0192] Module photovoltaic characteristics.

[0193] JV characteristics were acquired using a Keithley 2420 SourceMeter instrument under simulated AM 1.5G sunlight illumination (a xenon arc lamp combined with a calculated spectral mismatch factor of 1.05 for all tested TLSCs). Light intensity was calibrated using an NREL calibrated Si reference diode with a KG5 filter. Position-dependent EQE LSC The measurements were performed using a QTH lamp with a calibrated Si detector, monochromator, chopper and lock-in amplifier. -1 (L / 2d) EQE measured at each distance (d) LSC (λ), which accounts for the different angles faced by the edge-mounted PV at different excitation distances (d), where L is the LSC waveguide length. A range of EQEs were obtained using the same TLSC setup. LSC (λ) spectrum, and then the average spectrum is used to represent the entire device and integrated to determine the J from the corresponding JV characteristics of the same device. SC A matte black background was placed on the back of the TLSC device to eliminate illumination or reflections from the environment in both JV and EQE measurements (double pass). All TLSC devices were tested using the same Si or GaAs PV cells to eliminate any PV-to-PV performance differences.

[0194] Results and discussion

[0195] Figure 6CMapping of CO dissolved in chlorobenzene solution and embedded in a polymer matrix i Normalized absorption and emission spectra of 8DFIC. Both the absorption and emission spectra show a blue shift from solution to polymer matrix: the absorption peak shifts from 770 nm to 745 nm, and the emission peak shifts from 831 nm to 808 nm, with a Stokes shift of ~60 nm. The measured QY is 23 ± 1% in chlorobenzene solution and 25 ± 3% in the polymer matrix, with an increased absorption width. This is a relatively high QY for the NIR emission range, considering that most commercially available quantum dots emit ≤ 50% in this range. In comparison, CO i The 8DFIC band gap is reduced in pure films (as used in organic photovoltaics), so the reported external quantum efficiency (EQE) of PV devices can be extended to 1050 nm. When spin-coated as a pure layer on glass, the corresponding absorption spectrum does show an onset at ~1000 nm, but the quantum yield is significantly reduced to the point where the pure layer is not feasible in an LSC structure. Therefore, the application of this compound in doped LSC structures has been investigated.

[0196] More about CO i 8DFIC absorption, there are two possible explanations for the spectral shift from solution to polymer matrix film - aggregation and solvatochromic shift. Aggregation usually leads to a broadening of the absorption and thus a reduction in the band gap. Figure 8A In

[15] , the absorption spectra were measured in different polymer hosts (Eukitt vs. Shandon) and it was found that the absorption / band gap did not change, while the emission did shift slightly. Figure 8B As shown, aggregate solutions were also prepared by mixing THF with water and neat films. The absorption cutoffs for the aggregates and neat films are very close to each other (olive curve), showing a large red shift (~100 nm) compared to the monomers in solution. In contrast, the absorption cutoffs for the solution and polymer film are very close (blue curve). Therefore, this is more likely a solvatochromic shift related to the refractive index difference of the polymer matrix. CO in neat films and aggregates is significantly higher than in solution and polymer matrix. i The band gap of 8DFIC decreases, and the corresponding absorption onset also red-shifts.

[0197] The TLSC device was formed on an active area of 25.8 cm 2 The CO i 8DFIC molecules were dissolved in dichloromethane and uniformly mixed with the polymer host. This mixture was then drop-cast onto a glass plate to form CO i 8DFIC / polymer composite membrane. CO in dichloromethane solution was prepared at different concentrations i8DFIC to adjust the total light absorption in the NIR. Both Si and GaAs are used for edge-mounted PVs. Si is used to understand the performance trend, while GaAs is used to reduce heat loss and show the best performance. It should be noted that only when CO i GaAs can only be used when the 8DFIC / polymer PL cutoff is almost ideally located at 875nm relative to the GaAs EQE cutoff of 900nm. Laser-cut Si PV cells (or GaAs PV cells) are mounted on two orthogonal edges and connected in parallel, while the other two orthogonal edges are painted black (see Experimental Section). i 8DFIC concentration, and characterized its photovoltaic performance. For comparison, a TLSC with cyanine dye Cy7-NHS was added as a reference device. Figure 9A The current density-voltage (JV) characteristics of these TLSCs are shown. Figure 9B The average position-dependent external quantum efficiency (EQE LSC (λ) spectrum. Table 1 summarizes the photovoltaic parameters and aesthetic quality indicators (AVT and CRI). Compared with the “Cy7-NHS” control (1.01±0.07mAcm -2 ) compared to the lowest concentration of 50 mg L -1 The TLSC showed a 30% higher short-circuit current density (J SC :1.29±0.03mAcm -2 ), while showing similar open circuit voltage (VOC) and fill factor (FF). The corresponding AVT (84.4% vs. 88.2%) and CRI (91.3 vs. 92.0) are very close. i DFIC concentration increased to 150 mg / L -1 , J SC further increased to 2.07±0.08mAcm -2 , AVT (74.4%) and CRI (80.0) decreased slightly, and the corresponding PCE reached 0.54±0.03%. Further increasing the concentration to 300 mgL -1 The PCE was only slightly improved to 0.61 ± 0.05%, while the losses of AVT (59.7%) and CRI (63) increased significantly, with an increase in the blue tint.

[0198] Table 1. Photovoltaic and aesthetic quality parameters of TLSCs

[0199]

[0200] *TLSC edge-mounted with GaAs PV.

[0201] J extracted from JV characteristicsSC Value by EQE LSC Integration of (λ) SC OK (in Figure 9B middle). EQE LSC Peak position and Figure 6C The absorption spectrum of CO matches that of i 8DFIC has a neutral absorption distribution of visible light, partial EQE LSC The contribution comes from the visible light range. LSC During measurement, scattering caused by particle aggregation or direct illumination of edge-mounted PV can be directly measured from the EQE LSC As can be seen from the shape of the spectrum, Rayleigh scattering decreases with increasing wavelength, which superimposes a slanted background onto the illuminant peak. Direct illumination of the PV introduces a horizontal background into the illuminant peak that extends to the absorption cutoff of the edge-mounted PV. Both effects can lead to inaccurate EQE. LSC Measuring and overestimating the integrated J SC In EQE LSC Neither short-wavelength Rayleigh scattering nor long-wavelength direct illumination of edge-mounted PV cells was observed in the spectrum, confirming that the contribution to the EQE comes solely from the embedded CO i 8DFIC's PL.

[0202] To explore the CO i Effect of 8DFIC concentration on device scalability with three different CO i DFIC concentration (50 mg L -1 、150mgL -1 and 300mgL -1 ), and the TLSC system with “Cy7-NHS” (size: 10.16×10.16 cm) by position-dependent EQE LSC The EQE of each TLSC system was characterized as a function of the distance (d) from the excitation source to the edge-mounted PV cell. Multiple EQE scans were performed for each TLSC system with d increasing from 15 mm to 95 mm at 10 mm intervals. Corrected EQE LSC The peak values are extracted and plotted on Figure 9C middle.

[0203] "50mgL -1 The absolute absorption peak height of "(A(λ)%=49.6%)" was significantly lower than that of the "Cy7-NHS" control group (A(λ)%=88.6%). However, EQE LSC The peak heights are similar to each other, e.g. Figure 9BAs shown. Therefore, this 30% PCE improvement mainly stems from the broader absorption peak and higher QY. The excellent luminescence properties may be one of the reasons why it is such a high-performance acceptor in photovoltaic devices, where the high QY at a significantly low band gap means the reduction of non-radiative modes. For "150mgL -1 ", the increased absorption peak height (A(λ)%=80.3%) and width both lead to J SC With further increase in concentration, the absorption peak height reaches a stable level (for "300mgL -1 ”, A(λ)%=92.0%), but the increased width leads to coloration (low AVT and CRI) and greater reabsorption losses. This is reflected in the corresponding EQE LSC Spectrum: with "150mgL -1 Compared with 300mgL -1 "Showing a wider EQE LSC The peak width increases, but the peak height decreases. Normalized position-dependent EQE LSC The decay trend of the peak value helps to analyze the reabsorption loss behavior: "50mgL -1 ” shows the slowest decay trend due to the lowest reabsorption in this series. The “150 mg L -1 ” showed a faster decay curve, however, it was still slightly slower than the “Cy7-NHS” control. Finally, at the highest concentration, “300mgL -1 ” and “Cy7-NHS” have very similar “roll-off” behavior due to the highest reabsorption loss in the series. Considering scalability, aesthetic quality and photovoltaic performance, it was found that 150mgL -1 is the optimal concentration.

[0204] The origin of the enhancement relative to the prior art is further elucidated, as shown in Figures 10-10C and Table 2, by changing from the previously reported Cy7-NHS to CO i 8DFIC leads to a nearly doubling of the PCE, an improvement in QY from 20% to 25% (a 1.25-fold increase), and a 1.63-fold increase in wavelength-selective absorption.

[0205] Table 2. Cy7-NHS and 150 mg L -1 CO i Wavelength-selective absorption ratio, QY and Int.J of TLSCs of 8DFIC SC Comparison; factors reaching practical limits with and without visible light contribution.

[0206]

[0207] To explore the photovoltaic performance of TLSCs with different G factors, edge-mounted PVs, and illuminants, square TLSC devices with different G factors: waveguide length of 10.16 cm, thickness of 3.175 mm, and G factor of 8 were fabricated and tested. Figures 11A-11B As shown, the average integrated current density is 0.95 mA cm -2 , while in CO i 8DFIC concentration is 150mgL -1 1.78 mA cm -2 The PCE is expected to be 0.75%, with similar VOC and FF.

[0208] Furthermore, since the G factor and edge-mounted PV remain unchanged, CO i The PCE improvement of 8DFIC is consistently 80-100%, as shown in Table 3. Switching from Si to GaAs increases VOC and FF by a factor of 2.2 and 1.4, respectively. Therefore, it can be seen that the PCE improvement of both the emitter and the matching PV cell is equally important.

[0209] Table 3. Summary of photovoltaic parameters of TLSCs with different edge-mounted PV, G factors, and illuminants, e.g. Figures 11A-11B .

[0210]

[0211] like Figure 10C As shown in Table 2, increasing the QY from 25% to 100% can improve the PCE by a factor of 4 (from 1.3% to 5.2%). However, improving the UV and NIR absorption efficiency by sharper absorption spectrum cutoff (e.g., using dielectric mirrors) will lead to a 1.31-fold improvement (PCE from 5.2% to 6.8%), while further adjusting the emission spectrum to suppress reabsorption will lead to a 1.26-fold improvement (PCE from 6.8% to 8.6%). By absorbing 20% of the 435-675 nm visible light, the integrated J SC It can be further increased from 10.3mAcm -2 Increased to 13.5mAcm -2 (30% enhancement), thereby increasing PCE to >11%. This emphasizes several key points: 1) nearly identical QY can be achieved by improving absorption efficiency, and 2) selective collection of UV+NIR is more efficient at reaching peak efficiency. Overall, this class of materials can achieve optimized efficiencies above 10%, with modest gains of >5% (AVT >70%) possible as QY approaches 50%.

[0212] In these NIR selective harvesting TLSC devices, reabsorption remains the dominant loss mechanism, which may limit their application to smaller area applications. However, the Stokes shift and normalized absorption and emission spectra ( Figure 6C ) do not reflect different CO i 8DFIC concentration of the device is practically scalable. In addition, as Figures 12A-12F As shown, all transparent photovoltaic devices were examined using the photon balance at each wavelength, where the EQE LSC (λ)+T(λ)+R(λ)≤1. To quantify this behavior, a useful design parameter called overlap integral (OI) is introduced to conveniently correlate the reabsorption loss in the LSC system. i The emission widths of 8DFICs differ significantly from each other, and we normalize the OIs by their corresponding emission spectra to account for any spectral shape differences using equation (2):

[0213]

[0214] Where PL(λ) is the emission spectrum of the organic light emitting body in the polymer matrix film, OI * is the corrected overlap integral depending on thickness and / or concentration, the lower the OI * This helps improve efficiency and scalability. * The trend from lowest to highest level is: "50mgL -1 ”(0.249),“150mgL -1 ” (0.467), “Cy7-NHS” (0.470) and “300mgL -1 ” (0.618), which is consistent with the decay trend of these TLSCs.

[0215] To obtain independent EQE from TLSC devices LSC (λ), transmittance (T(λ)) and reflectance (R(λ)) spectral measurements confirm the validity of the photon balance, Figure 13A "150mgL -1 ” satisfies EQE at each wavelength LSC (λ)+T(λ)+R(λ)≤1. Figures 12A-12F The photon balance check of the remaining TLSC devices involved is shown. The position-dependent EQE is used in this relationship LSC Highest EQE in the spectrum LSC (λ) (obtained at minimum d, not Figure 9B ) to ensure that the entire series satisfies photon balance.

[0216] CIELAB color space coordinates (a* ,b * ) is a key figure of merit for quantifying the rendered color fidelity of transmitted light in the window industry. The incident AM 1.5G is located at the origin (0,0) (as a neutral point), and the TLSCs (a * ,b * ) location as Figure 13B As shown in Figure 2, the end absorption of the NIR absorption peak extends to the VIS (mostly red), so the a * and b * All are negative. -1 The coordinates of " and "Cy7-NHS" are very close, which can be observed in the TLSC photo ( Figure 13D ). With the i As the concentration of 8DFIC increases, the position moves away from the origin along an approximate straight line, and the rendered color gradually becomes bluer. At the highest concentration, the corresponding (a * ,b * ) moves outside the scale shown, indicating that "300mgL -1 ” no longer applies to glass systems.

[0217] The output voltage of the LSC device is determined by the edge-mounted PV cells. Ideally, using PV cells with a bandgap adjacent to the emitting edge of the emitter can effectively reduce voltage losses (reducing thermalization losses in PV) and improve the overall PCE. Further increasing the bandgap of edge-mounted PV may lead to a direct trade-off between output voltage and collectible current. i The emission peak edge of 8DFIC is around 900nm. GaAs is a nearly ideal PV with an EQE cutoff closest to CO. i 8DFIC emission peak edge. Therefore, as an example of this potential improvement, GaAs PV cells were integrated into the "150mgL -1 ” and “300mgL -1 "TLSCs to replace SiPVs. The JV curve is plotted on Figure 13C Medium. "150mgL -1 "The J measured for the GaAs device SC 1.54±0.05mAcm -2 , VOC significantly increased to 0.99±0.01V, FF was 81±1%, and PCE was 1.24±0.04%. -1 ” showed the same effect as “150mgL -1 "Very similar photovoltaic performance. Figure 13C The average EQE is provided in the insert of LSC spectrum;EQE LSCThe peak width is slightly wider, "300mgL -1 The peak height of " is lower than "150mgL -1 ", but the contribution of the visible light range is greater, so "150mgL -1 ” and “300mgL -1 "Integrated J SC The values are 1.78 mA cm -2 and 1.77 mA cm -2 , these values are consistent with the JV characteristics of J SC The values are very consistent.

[0218] LUE provides a metric for systematically comparing transparent PV installations with different overall levels of AVT on the same scale. Figure 13B In the inset, the LUE of the TLSC device is plotted as a function of AVT. For Si edge-mounted PVs, the LUE of the “Cy7-NHS” control TLSC is 0.21, while the CO i 8DFIC TLSCs LUE in "150mgL -1 " reaches a peak of 0.41. Further increasing the concentration can slightly increase PCE, but will significantly reduce AVT. For GaAs PV, "150mgL -1 ” and “300mgL -1 "The LUE values are 0.92 and 0.74 respectively. As far as we know, "150mgL -1 is the first report of a TLSC device with an AVT exceeding 70% and a PCE exceeding 1.2%. An overview of the performance parameters of previously reported LSC / TLSCs is shown in Table 4 for comparison.

[0219] Table 4. Summary of reported LSC / TLSC devices

[0220]

[0221]

[0222] To show that these non-fullerene acceptors are an attractive platform for LSC and TLSC development, a second popular non-fullerene acceptor, IEICO-4F ( Figure 14A ) were characterized and integrated as luminophores for TLSCs. The corresponding A(λ), PL(λ), and EQE in the polymer matrix LSC (λ)( Figures 14B-14D ) and CO i The 8DFIC is similar, with a slightly lower QY of 20 ± 2% (Eukitt), which reinforces the beneficial properties of this class of low-bandgap organic molecules.

[0223] Due to the near-ideal spectral absorption range and good coupling to GaAs (which is already close to the Shockley-Queisser limit), the practical limit of the device arrangement / molecular motif can be estimated by simply considering increasing the QY of the NIR emitter from 25% (measured value) to ~90%-100%. This can be achieved, for example, by chemically modifying the core molecular motif to reduce non-radiative modes through rigidification. In this limit, at the same high level of AVT, the PCE will reach an efficiency of slightly above 5%, while approaching the record 7% for opaque LSCs. Using this approach, a practical limit of over 10% can be achieved.

[0224] In summary, non-fullerene acceptors were introduced as luminophores into LSCs and TLSCs. i 8DFIC has become a popular acceptor in the field of organic photovoltaics and has been widely studied due to its excellent luminescence performance. i The effect of 8DFIC concentration on PCE, aesthetic quality, and scalability. After device optimization, the TLSCs showed a PCE exceeding 1.2%, an AVT exceeding 74%, and a CRI exceeding 80. This example reports the highest TLSC device efficiency at the highest visible transparency and emphasizes that the photoluminescent properties of these low-bandgap organic molecules provide enhanced TLSC performance.

[0225] Example 2

[0226] Visibly transparent luminescent solar concentrators (TLSCs) selectively harvest the ultraviolet (UV) and near-infrared (NIR) portions of the solar spectrum and convert the incident solar energy into electrical energy. Since the main applications of TLSCs include building envelopes, greenhouses, automobiles, signage, and mobile electronics, maintaining aesthetics and functionality in practical deployments is as important as achieving high power conversion efficiency (PCE). In this example, large-scale down-shifted phosphorescent nanoclusters (NCs) and fluorescent organic molecules are introduced into the TLSC system as UV and NIR selective harvesting luminophores, respectively. UV and NIR dual-band selective harvesting TLSCs are demonstrated to have a PCE exceeding 3%, while the average visible transmittance (AVT) exceeds 75% and the color rendering index (CRI) is close to 90. Due to the unique wavelength selectivity and the effective utilization of the invisible portion of the incident solar spectrum, this example reports the highest TLSC PCE at the highest transparency, demonstrating a path to the commercialization of transparent solar technology.

[0227] introduce

[0228] Building-integrated photovoltaics (BIPV) can convert new and existing infrastructure surfaces into a source of electricity generation, significantly reducing electrical losses in transmission. To maximize the output of incident solar energy, integration should be deployed across the entire building envelope, including the exterior walls and roof areas. For siding and window areas, this requires BIPVs to not compromise aesthetic quality. Visibly transparent photovoltaics (TPV) technology selectively harvests the UV and NIR parts of the solar spectrum and allows visible (VIS) light to pass, converting the invisible portion of light into electricity to meet on-site energy needs. In addition, TPVs can be easily integrated into other smaller areas, including greenhouses, (electric) vehicles, (autonomous) mobile electronics, and textiles, significantly improving energy efficiency.

[0229] The practical deployment of TPV technology requires both high PCE and good aesthetic qualities (high AVT and CRI). Therefore, maximizing light harvesting in the invisible portion of the solar spectrum is beneficial, while precisely tuning the absorption cutoff at the UV / VIS and VIS / NIR boundaries to maximize visible light transmission (435-675 nm). Over the past five years, significant efforts have been made to achieve both high PCE and visible transparency in TPVs. For example, the band gaps of organometallic halide perovskite materials have been carefully tuned through compositional engineering for UV-selective TPVs. A series of novel low-bandgap polymer donors and non-fullerene acceptors have been applied to organic photovoltaic devices, demonstrating excellent photovoltaic performance and significant near-infrared selectivity. Optical outcoupling layers for visible light photons, distributed Bragg reflectors for near-infrared photons, and various types of transparent electrodes have been employed to simultaneously improve visible light transparency and invisible light utilization. Currently, the PCE of thin-film TPVs has reached approximately 8-10%. However, due to significant dependent absorption in electrodes, active layers, and nonideal wavelength selectivity, the highest reported AVT is approximately 40-50%.

[0230] Alternatively, transparent luminescent solar concentrators (TLSCs) optically transfer solar energy conversion to edge-mounted conventional PV cells via waveguide photoluminescence (PL). The structural simplicity of TLSCs with varying wavelength selectivity, without any electrodes on the active area, enables the highest possible visible transparency, thus avoiding several challenges of thin-film TPVs and simplifying fabrication. Most previous work on TLSCs with NIR harvesting has exhibited absorption profiles that limit UV harvesting, with PCEs (power consumption coefficients) of up to approximately 1%, AVTs (autonomous variable time-variances) exceeding 70%, and light utilization efficiencies (LUEs, equal to PCE x AVT) of 0.7. The highest reported semitransparent LSC device exhibits a PCE of 2.2%, an AVT of 44% (LUE of 0.97), and a brown hue. A variety of luminophores with varying wavelength selectivity can be incorporated into the LSC waveguide to maximize the spectral coverage of light harvesting, enhance photovoltaic performance, and balance color neutrality. Here, highly luminescent phosphorescent nanoclusters and fluorescent organic molecules are introduced into TLSCs as separate UV- and NIR-selective harvesting luminophores, respectively. The nanoclusters selectively harvest UV photons while exhibiting a QY greater than 70% and a substantial downshift of the emission toward the NIR. To efficiently pair these emitters and prevent dependent reabsorption losses of the nanocluster emission in NIR-absorbing organic fluorophores, an effective strategy for isolating the absorption / emission bands is demonstrated. Due to the efficient utilization of invisible photons and the high photoluminescence quantum yield (QY) of the luminophores, the corresponding dual-band selective harvesting TLSCs exhibit a PCE exceeding 3%. The unique UV and NIR selectivity provides the TLSCs with excellent aesthetic quality (AVT exceeding 75% and CRI approaching 90). These dual-band TLSCs also show good photostability with minimal degradation under 300 hours of constant illumination. This example not only reports the TLSC device with the highest PCE (to our knowledge), but also demonstrates a novel design for the efficient utilization of the solar spectrum in an aesthetic manner.

[0231] experiment

[0232] Nanocluster synthesis.

[0233] 1) Cs2Mo6I 14 MoI2 powder (2A Biotech) and CsI powder (Sigma-Aldrich) were uniformly mixed in a stoichiometric ratio of 3:1. The mixture was then transferred to a quartz ampoule (12 cm long, 1.5 cm diameter) and sealed under vacuum. The ampoule was heated at a reaction temperature of 750°C for 72 hours to form Cs2Mo6I 14 After cooling to room temperature, the powder in the ampoule was dissolved in acetone (wine-red clear solution) and the undissolved impurities (unreacted black powder) were filtered out. Cs2Mo6I was dried by rotary evaporation.14 Acetone solvent in solution to form red Cs2Mo6I 14 powder.

[0234] 2) Cs2Mo6I8(CF3CF2COO)6: Weigh Cs2Mo6I 14 and dissolved in acetone, and then silver pentafluoropropionate (CF3CF2COOAg) (Sigma-Aldrich) was added to Cs2Mo6I in a stoichiometric ratio of 6:1. 14 The reaction was kept in the dark under nitrogen atmosphere for 48 hours. After the ligand exchange reaction, the precipitated AgI was filtered out and the solution (cider-colored) was dried by rotary evaporation to obtain orange Cs2Mo6I8(CF3CF2COO)6 powder. Cs2Mo6I8(CF3COO)6 or Cs2Mo6I8(CF3CF2CF2COO)6 nanoclusters can be prepared by making Cs2Mo6I 14 The reaction with CF3COOAg or CF3CF2CF2COOAg is prepared in a similar manner.

[0235] 3) Synthesis of CO as described above i 8DFIC. Based on Figure 15 BODIPY was synthesized using the reaction scheme provided in .

[0236] Module manufacturing.

[0237] 1) UV component: Weigh Cs2Mo6I8(CF3CF2COO)6 nanocluster powder and dissolve it in ethanol to prepare a solution of the target concentration. The ethanol solution is then mixed with mounting medium (Fluoroshield F6182, Sigma-Aldrich) at a volume ratio of 1:2.

[0238] 2) NIR component: BODIPY or CO i DFIC powder was dissolved in dichloromethane to prepare a solution. The dichloromethane solution was mixed with mounting medium (Shandon, Thermo Fisher Scientific) at a volume ratio of 1:1. The mixture was drop-cast on a 50.8 mm × 50.8 mm × 6.35 mm (for JV characterization and average EQE) LSC measurements) and 101.6mm×101.6mm×6.35mm (for position-dependent EQE LSC) on a borosilicate glass plate and dried for 6 h in a glove box filled with nitrogen (O2, H2O <1 ppm). After drying, the two components were encapsulated together around the edges by UV-curable epoxy resin (DELO) so that the two composite films were facing each other. Edge-mounted GaAs PV (Alta devices) were used as is. For JV measurements, two PV strips were mounted on orthogonal edges using refractive index matching gel (Thorlabs) to connect the PV strips to the waveguide edge and connected in parallel. The remaining two edges were painted black to block light and internal reflections of light. For EQE LSC For measurement, a PV strip is attached to one edge of the waveguide and the other three edges are painted black.

[0239] Optical properties.

[0240] The specular transmittance (T(λ)) of the TLSC device was measured using a dual-beam Lambda 800 UV / VIS spectrometer in transmission mode. No reference sample was placed on the reference beam side for solid film TLSC transmittance measurements. The reflectance (R(λ)) of the TLSCs was also measured using a Lambda 800 UV / VIS spectrometer with the specular accessory mounted on the sample beam side. The absorption spectrum was obtained by the following equation: A(λ) = 1-T(λ) - R(λ). The absorption spectra of NC, BODIPY, and CO in the polymer matrix were measured using a PTI QuantaMaster 40 fluorescence spectrophotometer at 400 nm, 650 nm, and 650 nm excitation, respectively. i PL of 8DFIC. Photoluminescence quantum yield was measured using a Hamamatsu Quantaurus fluorimeter.

[0241] Module photovoltaic characteristics.

[0242] JV characteristics were obtained under simulated AM 1.5G solar illumination using a Keithley 2420 SourceMeter instrument (Xenon arc lamp combined with a calculated spectral mismatch factor of 1.05 for all tested TLSCs). Light intensity was calibrated using an NREL calibrated Si reference diode with a KG5 filter. Position-dependent EQE LSC The measurements were performed using a QTH lamp with a calibrated Si detector, monochromator, chopper and lock-in amplifier. -1 (L / 2d) EQE measured at each distance (d) LSC (λ) is corrected, which accounts for the different angles faced by the edge-mounted PV at different excitation distances (d), where L is the LSC waveguide length. A range of EQEs are obtained using the same TLSC setup. LSC(λ) spectrum, and then the average spectrum is used to represent the entire device and integrated to determine the J from the corresponding JV characteristics of the same device. SC A matte black background was placed on the back of the TLSC device to eliminate illumination or reflections from the environment in both the JV and EQE measurements (double pass). All TLSC devices were tested using the same GaAs PV cells to eliminate any PV-to-PV performance differences.

[0243] result

[0244] The dual-band TLSC device consists of two separated waveguides, such as Figure 16A As shown, one waveguide contains the UV component and the other contains the NIR component. An air gap is used to optically isolate the waveguide emission in each panel to prevent adsorption and increase scalability. For more practical deployments, the air gap can be replaced with a low-index polymer, metal oxide, glass, or glue with little change in performance.

[0245] The top UV component is based on highly phosphorescent hexa-core nanoclusters ( Figure 16B The chemical structure of Cs2Mo6I8(CF3CF2COO)6NC is shown. Details of the synthesis are provided in the experimental section. Waveguides were fabricated by drop-casting the NC / polymer mixture onto square borosilicate glass plates to form a uniform composite film. The normalized absorption and emission spectra of the NC in the polymer are also shown. Figure 16B The spectra show a band absorption cutoff at the UV / VIS boundary and a NIR emission onset at the VIS / NIR boundary with a substantial downshift of over 300 nm and a corresponding QY of 75 ± 5 in the polymer matrix, which makes NCs good UV-selective harvesting luminophores for TLSC applications.

[0246] The bottom waveguide is based on an organic dye molecule. In organic and molecular semiconductors, light absorption originates from transitions from the ground state to excited molecular orbitals. The energy differences between the excited molecular states form discontinuities in the density of states. Therefore, these energy gaps can be tuned to transmit visible photons in TPV applications. In this work, two different organic emitters were used as NIR selective harvesters: CO i 8DFIC (also known as O6T-4F), which has been developed as a non-fullerene acceptor with excellent performance in organic photovoltaics; and a new BODIPY molecule with high quantum yield in the NIR (synthesis details are provided in the experimental section). The molecular structures, normalized absorption spectra, and emission spectra of these NIR components in the polymer matrix are shown in Figure 16C and Figure 16D Similarly, NIR selective harvesting waveguides were also fabricated by drop-casting a dye / polymer mixture onto a glass plate to form a uniform composite film. iThe absorption peak of 8DFIC is at 745 nm and the emission peak is at 808 nm, showing a Stokes shift of about 60 nm and a QY of 25 ± 3 in the polymer matrix. i Compared to 8DFIC, BODIPY exhibits a narrower absorption peak and smaller Stokes shift, but a significantly higher QY of 40 ± 3%, the highest value in the NIR emission range. Because oxygen can absorb triplet excitons to form singlet oxygen species, thereby increasing the nonradiative recombination rate in NCs, the QY decreases significantly when exposed to oxygen. Therefore, it is necessary to encapsulate the waveguide with epoxy along the waveguide edge, with the two composite films facing each other.

[0247] For LSCs, it is ideal to choose edge-mounted PV cells whose band gap is adjacent to the emitting edge of the emitter. This allows the collection and conversion of all waveguide PL while minimizing voltage losses due to thermalization. Figure 16B 、 16C As shown in 16D, NC, CO i All three emission edges of 8DFIC and BODIPY are below 900nm, making GaAs a near-ideal choice for edge-mounted PV cells for these emitters to maximize performance. Therefore, GaAs cells were mounted on one edge of the dual waveguide for EQE measurements and on both sides for JV measurements, both corrected for an equivalent four-edge mounting.

[0248] A combination of two luminophores (NC+CO i 8DFIC and NC+BODIPY) dual-band TLSC devices were fabricated and their photovoltaic performance was characterized. For comparison, a TLSC containing only NC (10 mg / mL) was added as a reference device. These TLSCs (active area 5.08 × 5.08 cm) were measured under AM1.5G illumination. 2 )'s current density-voltage (JV) characteristics are as follows Figure 17A The TLSC of NC alone showed 2.5 ± 0.2 mA cm -2 The short-circuit current density (J SC ), an open circuit voltage (VOC) of 1.01 ± 0.01 V, and a fill factor (FF) of 80 ± 1%, resulting in a PCE of 2.0 ± 0.1%. When organic dyes were added to TLSCs with the same UV composition (NC concentration was kept at 10 mg / mL), for NC+CO i 8DFIC and NC+BODIPY TLSCs, J SC The values were increased to 3.6±0.2mAcm -2 and 3.8±0.1mAcm -2, while showing similar VOC and FF, resulting in corresponding PCEs of 2.9±0.1% and 3.01±0.07%, respectively. The average position-dependent external quantum efficiency (EQE LSC (λ)) spectrum as Figure 17B For TLSC with only NC, EQE LSC The contribution comes only from the UV selective light absorption of NC. LSC Neither Rayleigh scattering caused by particle aggregation nor direct illumination of the edge-mounted PV is observed in the profile. This also confirms that the haze of the device is very small (<10%). i 8DFIC and NC+BODIPY TLSCs, UV and NIR peaks appear in their corresponding EQE LSC In the spectrum, this is the result of dual-band selective acquisition. LSC The peak position matches the absorption spectrum of the corresponding luminophore. LSC The peak heights were determined from the luminophore QY values and the absolute absorption spectra. For the same UV component, the NC contributions of all three TLSCs were almost identical. For these device dimensions, the CO i Compared with 8DFIC, the slightly higher absolute absorption peak and significantly higher QY of BODIPY lead to significantly higher EQE LSC As one of the most important consistency checks for any photovoltaic device, the J peak extracted from the JV characteristics SC Values from EQE LSC Integration of (λ) SC ( J SInCt) determined. Only NC, NC+CO i The values of 8DFIC and NC+BODIPY TLSCs were 2.42 mA cm -2 、3.60mAcm -2 and 3.89 mA cm -2 , and they are related to J in the JV curve SC Very good match. Although the EQE of BODIPY in NC+BODIPY TLSC LSC Peak higher than NC+CO i 8DFIC TLSC, however, CO i The broad absorption width of 8DFIC compensates for its lower absorption peak and QY, resulting in similar contributions from the NIR components.

[0249] A range of position-dependent EQEs LSC The spectrum can be used to understand the scalability of the LSC system. The dual-band TLSC system was fabricated in a larger size (10.16×10.16cm 2 ), NC+COi EQE of 8DFIC and NC+BODIPY TLSCs at different d LSC The series are plotted on Figure 17C and 17D where d is the distance between the incident excitation beam along the centerline of the square waveguide and the edge-mounted photovoltaic cell (see the Experimental section for details). Figure 17E and 17F In the , UV and NIR peaks of each individual scan are extracted, normalized and plotted as a function of d. NC only, CO only i 8DFIC and BODIPY-only TLSCs were also fabricated as references. With the large amount of NC down-shifted, the reabsorption loss can be neglected, making NC-only, NC+CO i The UV peaks of 8DFIC and NC+BODIPY TLSCs remain almost unchanged with increasing d. It should be noted that NC can be replaced by an efficient downconverter so that two or more NIR or IR photons are emitted for each absorbed UV photon. However, due to the CO i The overlap between the absorption and emission spectra of 8DFIC and BODIPY is significantly stronger, and the reabsorption loss leads to a more pronounced attenuation of the NIR peak compared to the UV peak. Figure 17E and 17F As shown, the UV and NIR peak attenuation behaviors of dual-band TLSCs are similar to those of NC only and CO only. i 8DFIC and BODIPY-only TLSCs are very similar. Given that EQE LSC The similarity of the attenuation trends in each range of the spectrum and the isolation of the waveguides effectively achieve total internal reflection within each waveguide, allowing the UV and NIR components to operate independently.

[0250] Aesthetic quality is as important as the photovoltaic performance of any TPV device, which determines whether the TPV device can be deployed in certain practical applications. Figure 18A NC only, NC+CO are drawn in i Transmission spectra (T(λ)) of 8DFIC and NC+BODIPY TLSCs and the photopic response of the human eye (V(λ)) are shown for comparison. NC shows an absorption cutoff edge at the UV / VIS boundary, while BODIPY shows an NIR band absorption onset at the VIS / NIR boundary. However, CO i 8DFIC's broad NIR band absorption extends into the red / near infrared (NIR) range, resulting in lower visible light transmittance and a slight blue tint. T(λ) is used to quantify the main quality indicators of aesthetic quality: AVT, CRI and CIELAB color space coordinates (a * ,b *). Due to its good UV selectivity, the NC-only TLSC showed an AVT of 81.9% and a CRI of 91.3. For dual-band TLSCs, NC+CO i The AVT and CRI of 8DFIC TLSC decreased to 65.6% and 82.9, respectively. Due to the better NIR selectivity of BODIPY, the AVT and CRI of NC+BODIPY TLSC increased to 75.8% and 88.3, respectively.

[0251] discuss

[0252] The effects of NC concentration on NC alone, NC+CO i Effect of 8DFIC and NC+BODIPY TLSCs on aesthetic quality and photovoltaic performance. CIELAB color space coordinates (a * ,b * ) is commonly used to evaluate the acceptable tinting range of products in the glass and glazing industry. As the "reference light source" for TPVs, the incident AM 1.5G is located at the origin (0,0) (colorless or neutral), and (a * ,b * ) coordinates in Figure 18B These TLSCs were divided into three groups: NC only, NC+CO i 8DFIC group and NC+BODIPY group, NC concentration (1, 2, 5, 10 and 20 mg / mL) was the only variable within each group. i 8DFIC and TLSCs containing only BODIPY were used as references. Figure 18B As shown, CO i Incorporation of 8DFIC or BODIPY leads to a * This is due to the extended NIR absorption into the red range. i 8DFIC and NC+BODIPY TLSCs * As the NC concentration increased from 1 to 5 mg / mL, and if the concentration was further increased above 10 mg / mL, it resulted in a decrease in the aesthetic quality of TLSC and |b * |The value dropped significantly to the point where it was not very acceptable to the window industry (>10).

[0253] Visible light absorbing semiconductor materials can also be used as active layers in TPV applications. Active layers with sufficiently thin thickness or micro-segmented structures allow a portion of visible light to be transmitted, resulting in partial visible light transparency. However, there is a direct trade-off between photovoltaic performance and visible light transmission. Figure 18B As shown, any absorption distribution within the range of 435-675nm may lead to a sharp drop in AVT, CRI, and (a* ,b * ) increases with the deviation from the CIELAB origin. Therefore, this type of device is sometimes called a "semi-transparent" PV or non-wavelength selective TPV. Although the theoretical Shockley-Queisser (SQ) limit of an opaque PV is 33.1%, the PCE of a non-wavelength selective TPV approaches 0% as the AVT increases to 90%. The SQPCE limit line of a non-wavelength selective TPV is shown in Figure 19A As shown. The wavelength selective TPV or TLSC that only collects UV (<435nm) and NIR photons (>675nm) has an SQ PCE limit of more than 20% (20.6%) and an AVT close to 100% (99.4%). The area to the right of the SQ limit line reflects the target PCE and AVT combination that can only be achieved by wavelength selective methods. All three groups of TLSCs (including CO only) i The PCE values of 8DFIC and BODIPY reference only) are plotted as a function of AVT (60-100% range) in Figure 19A We note that only CO i The 8DFIC and BODIPY-only reference TLSCs do not require encapsulation with an additional glass plate. The simple structure reduces their reflection losses, thereby improving the overall transmittance across the entire spectrum. Among all these devices, the BODOIPY-only TLSC is closest to the SQ PCE limit line due to its good NIR selectivity. As the NC concentration increases from 1 to 10 mg / mL, the PCE and AVT trend lines of the NC-only group remain almost parallel to the SQ PCE limit line until it begins to deviate above 10 mg / mL due to terminal absorption into the visible light. As the NC concentration increases, the NC+CO i The 8DFIC group and the NC+BODIPY group also showed similar trends. The addition of the NIR component significantly improved the PCE of the dual-band selective collection TLSC system by more than 3% (up to 3.4%) and slightly reduced the AVT. Light utilization efficiency (LUE, defined as the product of PCE and AVT) provides a metric for systematically comparing TPVs with different levels of AVT values on the same scale. The LUE of all TLSCs as a function of their corresponding AVT and the SQ LUE limit line are plotted in Figure 19B Although the air gap or extended NIR absorption into the red range leads to a slightly lower AVT level, the LUE is still significantly improved due to dual-band selective harvesting, i.e., the dual-band TLSC system can more efficiently utilize invisible photons to generate electricity while exhibiting good aesthetic quality.

[0254] Considering methods to further improve performance to approach the limits of TPV and TLSC. The photon flux <435nm is only about 8% of AM1.5G. Collecting light >435nm will quickly lead to a yellowish or brownish color (positive b * values), which is unacceptable for most window applications. In contrast, the NIR range between 675nm and the absorption cutoff of edge-mounted PV cells (e.g. Si, GaAs, etc.) coincides with the peak of the AM 1.5G photon flux and has greater power generation potential. Even if the absorption extends into the red range, the resulting blue tint (negative a * This provides greater design freedom for NIR selective harvesting luminophores and can even help compensate for poor b values caused by excessive yellow tints. * In recent years, the QY of various UV-absorbing luminophores, including quantum dots and nanoclusters, has gradually increased to over 80%, but further improvement is not only challenging but also quite limited. In contrast, the QY of NIR luminophores is currently in the range of 20-35%. However, there is still great hope to increase the QY to 60-80% through chemical design. For example, Figure 17B As shown, for NC+BODIPY TLSC, although the NC peak is much stronger than the BODIPY peak (due to the higher QY of NC and smaller reabsorption loss), the contribution of the NIR component is comparable to that of the UV component (2.4 mA / cm 2 vs.1.5mA / cm 2 ). Therefore, future efforts in TLSC development should focus on: 1) improving the QY of NIR selective harvesting luminophores (allowing a 2-3x increase in NIR contribution without changing aesthetics); 2) having significant wavelength selectivity near the UV / VIS and VIS / NIR boundaries to achieve higher visible light transmittance and better color rendering; 3) separating the absorption and emission spectra of NIR luminophores to suppress reabsorption losses. Considering the QY of dual-band TLSCs of ~80% in both UV and NIR components and the ideal wavelength selectivity, J SC The majority of the contribution (>75%) should come from its NIR component, with an overall PCE of ~7% expected, along with AVT>80% and CRI>90. Figure 19A and 19B As shown, this PCE and AVT combination lies above the SQPCE and LUE lines, making it suitable for deployment in most practical applications.

[0255] Photon balance is a necessary consistency check to confirm that independent measurements include the EQE at each wavelength LSC The photon balance of all TLSC devices in this work is Figures 20A-20CThe results are consistent with those shown in Figure 2. Long life performance is another key feature in real deployment. i Photostability of 8DFIC and NC+BODIPYTLSCs. Figures 21A-21C The results of NC only, NC+CO under constant illumination are shown in i Normalized absorption peak and EQE of the absorption spectra (A) of 8DFIC and NC+BODIPY LSC and internal quantum efficiency (IQE LSC ) as a function of time. After 300 h of continuous illumination, all parameters remained almost unchanged, thus, these TLSC devices exhibited excellent photostability.

[0256] In summary, a dual-band selective harvesting TLSC device was designed and demonstrated by combining highly emissive phosphorescent hexanuclear metal halide nanoclusters with organic luminophores for UV and NIR selective harvesting. Harvesting invisible photons from the UV and NIR portions of the solar spectrum resulted in a PCE >3%, and precise wavelength selectivity at the UV / VIS and VIS / NIR boundaries led to an AVT >75% and a CRI approaching 90. With further improvements in NIR quantum yield, this approach resulted in device efficiencies approaching 10%. With high photovoltaic performance, excellent aesthetic qualities, and long-term photostability, this example reveals the vast potential of TLSC technology as a power generation source for a variety of applications, providing a pathway for the efficient and ubiquitous utilization of solar energy.

[0257] For the purpose of illustration and description, the description of the above-mentioned embodiments has been provided. It is not intended to be exhaustive or limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments, even if not specifically shown or described. It can also be changed in many ways. These changes should not be considered as departing from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A transparent luminescent solar concentrator comprising: luminous body; a waveguide that guides light emitted from the light emitting body; as well as a photovoltaic assembly operatively coupled to the waveguide, wherein the transparent luminescent solar concentrator has a light utilization efficiency (LUE) greater than or equal to 1, wherein, The luminophore has the strongest maximum absorbance and the strongest peak emission at a wavelength greater than or equal to 650 nm; The light emitters are embedded within the waveguide, disposed directly on the waveguide, or provided in a film disposed on the waveguide.

2. The transparent luminescent solar concentrator according to claim 1, wherein: The transparent luminescent solar concentrator has an average visible transmission (AVT) greater than or equal to 50% and a color rendering index (CRI) greater than or equal to 80 at normal incidence to the waveguide.

3. The transparent luminescent solar concentrator according to claim 1, wherein: The transparent luminescent solar concentrator has a power conversion efficiency (PCE) greater than or equal to 1% and a |b less than or equal to 25. * |value.

4. The transparent luminescent solar concentrator according to claim 1, wherein: The transparent luminescent solar concentrator has an average visible light transmission (AVT) greater than or equal to 60%.

5. The transparent luminescent solar concentrator according to claim 1, wherein: The transparent luminescent solar concentrator has a haze of less than or equal to 10%.

6. The transparent luminescent solar concentrator according to claim 1, wherein: The luminophore is a non-fullerene acceptor, boron-dipyrromethene (BODIPY) or a combination thereof.

7. The transparent luminescent solar concentrator according to claim 6, wherein: The luminophore is a non-fullerene acceptor, and the non-fullerene acceptor is 2,2'-[[4,4,11,11-tetrakis(4-hexylphenyl)-4,11-dihydrothieno[2',3':4,5]thieno[2,3-d]thieno[2",3"":4",5"']thieno[2",3"':4",5"]pyrano[2",3":4',5']thieno[2',3':4,5]thieno[3,2-b]pyran-2,9-diyl]bis[methylene(5,6-difluoro)(CO i 8DFIC), 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indeno[1,2-b:5,6-b']dithiophene)(ITIC), 2,2'-[[4,4,9,9-tetrakis(4- hexylphenyl)-4,9-dihydro-s-indeno[1,2-b:5,6-b']dithieno-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thienyl]methylene(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile] (IEICO-4F), or a combination thereof.

8. The transparent luminescent solar concentrator according to claim 1, further comprising: a second luminous body; and a second waveguide that guides light emitted from the second light emitting body, wherein the second waveguide is positioned adjacent to the waveguide such that the waveguide receives light transmitted through the second waveguide, and The first waveguide and the second waveguide are separated by a gap filled with air or a visible transparent material.

9. The transparent luminescent solar concentrator according to claim 8, wherein: The visible transparent material has a refractive index (n) less than or equal to 1.

3.

10. The transparent luminescent solar concentrator according to claim 8, wherein: The second light emitting body has a quantum yield (QY) greater than or equal to 50%.

11. The transparent luminescent solar concentrator according to claim 8, wherein: The second luminophore has the strongest maximum absorbance at a wavelength less than or equal to 450 nm and the strongest peak emission at a wavelength greater than or equal to 650 nm.

12. The transparent luminescent solar concentrator according to claim 11, wherein: The second luminescent body includes nanoclusters.

13. The transparent luminescent solar concentrator according to claim 11, wherein: The waveguide and the second waveguide are configured such that incident light first passes through the second waveguide and then passes through the waveguide.

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