Color filter assemblies for efficient and angle-robust photovoltaic devices

Abstract

An angularly insensitive / angularly robust color filter assembly for use with a photovoltaic device to produce a decorative and colored photovoltaic device assembly is provided. The filter can be passive or active, with an ultrathin reflective layer of a high refractive index material such as amorphous silicon (a-Si). The passive filter can have a transparent first pair and a second pair of dielectric materials surrounding the ultrathin reflective layer. The active filter can have a transparent first electrode and a second electrode surrounding the ultrathin reflective layer and a first doped hole / electron transport layer and a second doped hole / electron transport layer. The filter can transmit a portion of the electromagnetic spectrum and reflect a portion of the electromagnetic spectrum to produce a reflective color output with minimal angular dependence. An angularly insensitive color photovoltaic device assembly including a passive or active color reflective filter and a photovoltaic device with high power conversion efficiency (e.g., ≥18%) can also be envisioned. The photovoltaic device can include a photosensitive layer comprising crystalline silicon (c-Si).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 583,966, filed on November 9, 2017. The entire disclosure of the above application is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to highly efficient and angularly robust colored angle-insensitive filter assemblies as well as angle-insensitive colored photovoltaic device assemblies including passive colored reflective filters and photovoltaic devices and angle-insensitive colored photovoltaic device assemblies including active colored reflective filters and photovoltaic devices. Background Art

[0004] This section provides background information related to the present disclosure which is not necessarily prior art.

[0005] Photovoltaic devices (PV) hold great promise as an alternative to traditional fossil fuels by providing the ability to harvest inexhaustible solar energy. To increase PV viability, efforts are ongoing to increase power conversion efficiency (PCE) and reduce production costs. PVs based on crystalline silicon (c-Si) photosensitive materials that absorb wavelengths up to about 1100 nm offer tremendous potential not only due to the abundance and availability of the materials, but also due to the high PCEs (e.g., in excess of 20%) that can be achieved. However, solar cells / PVs incorporating c-Si photosensitive materials have a dark, dull appearance that significantly hinders their use in a variety of applications, including, as non-limiting examples, for decorative purposes on vehicles and building exteriors. Given the poor aesthetics of current solar cells, many opportunities to utilize available solar energy are missed, which is currently wasted.

[0006] A variety of schemes have been proposed, such as dye-sensitized solar cells (DSSC) and organic PV (OPV) to produce colored solar cells. However, these colors depend largely on the type of materials used, and the color tunability is also very limited. In addition, the organic components contained in such structures are highly sensitive and have life problems, for example, special passivation techniques are required to resist oxygen and moisture. Recently, schemes have been developed to introduce color filters into PV panels to allow electricity to be generated by simultaneously harvesting the absorbed light. However, the color filters involved in these solar cells are based on Fabry-Perot (FP) interferometer cavities or plasma resonances, which produce colors that are highly sensitive to viewing angles (e.g., varying with viewing angle and incident light polarization) and are therefore undesirable for decorative coatings. In addition, it is also a problem to scale up such nanostructured plasma color filters to large areas. In addition, one-dimensional (1D) layered solar cells that integrate amorphous silicon (a-Si) with angle- and polarization-insensitive color features into PV assemblies have been used. The non-iridescent colored appearance can be attributed to the nontrivial reflection phase change at the interface of a-Si and metal, which thus compensates for the propagation phase of light propagating through the ultra-thin a-Si layer (<30nm). However, due to the small amount of light absorbed, the power conversion efficiency (PCE) of such semi-transparent PV panels is limited to only about 2%. Therefore, it is desirable to develop multifunctional solar cells / PVs that can provide excellent performance with high PCE while providing attractive decorative aesthetics and design features. Summary of the invention

[0007] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0008] In one variation, the present disclosure contemplates a color filter for use with a photovoltaic device. The filter includes an ultrathin reflective layer defining a first side and a second side. The filter also includes a transparent first pair of dielectric materials adjacent to the first side of the ultrathin reflective layer, wherein the first pair includes a first layer of dielectric material and a second layer of a different dielectric material. A transparent second pair of dielectric materials is disposed adjacent to the second side of the ultrathin reflective layer, wherein the second pair includes a third layer of dielectric material and a fourth layer of a different dielectric material. The filter is capable of transmitting a first portion of an electromagnetic spectrum having a first predetermined wavelength range and reflecting a second portion of an electromagnetic spectrum having a second predetermined wavelength range to produce a reflected output.

[0009] In one aspect, the reflectance output exhibits minimal angular dependence such that the second wavelength range varies by less than or equal to about 80 nm at incident angles of about 0° to about 60° relative to the color filter to form an angle-insensitive color filter.

[0010] In one aspect, the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material.

[0011] In one aspect, the ultra-thin reflective layer has a thickness less than or equal to about 15 nm.

[0012] In one aspect, the ultra-thin reflective layer has a thickness of greater than or equal to about 5 nm to less than or equal to about 12 nm.

[0013] In one aspect, the reflected output having the second predetermined wavelength range is in the visible range and has a color selected from red, green, blue, and combinations thereof.

[0014] In one aspect, the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), titanium oxide (TiO2) and silicon dioxide (SiO2), zinc oxide (ZnO), hafnium oxide (HfO2), molybdenum trioxide (MoO3), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), tungsten trioxide (WO3), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and a polymer having a refractive index greater than or equal to about 1.6.

[0015] In one aspect, the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), zinc selenide (ZnSe), titanium oxide (TiO2) and silicon dioxide (SiO2).

[0016] In one aspect, the first layer comprises silicon dioxide (SiO2), the second layer comprises titanium oxide (TiO2), the third layer comprises titanium oxide (TiO2), and the fourth layer comprises silicon nitride (Si3N4).

[0017] In one aspect, the first layer comprises silicon nitride (Si3N4), the second layer comprises zinc selenide (ZnSe), the third layer comprises zinc selenide (ZnSe), and the fourth layer comprises silicon nitride (Si3N4).

[0018] In one aspect, the thickness of the first layer is greater than or equal to about 50 nm to less than or equal to about 300 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 50 nm to less than or equal to about 300 nm.

[0019] In one aspect, the reflective output having the second predetermined wavelength range exhibits a blue color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 50 nm to less than or equal to about 200 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 150 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 150 nm, and the thickness of the fourth layer is greater than or equal to about 50 nm to less than or equal to about 200 nm.

[0020] In one aspect, the reflective output having the second predetermined wavelength range exhibits a green color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 100 nm to less than or equal to about 200 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 100 nm to less than or equal to about 200 nm.

[0021] In one aspect, the reflective output having the second predetermined wavelength range exhibits a red color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 100 nm to less than or equal to about 300 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 100 nm to less than or equal to about 300 nm.

[0022] In certain variations, the present disclosure also provides an angle-insensitive color photovoltaic device assembly including a color reflective filter and a photovoltaic device. The color reflective filter includes an ultrathin reflective layer defining a first side and a second side. A transparent first pair of dielectric materials is disposed adjacent to the first side of the ultrathin reflective layer, wherein the first pair includes a first layer of dielectric material and a second layer of a different dielectric material. A transparent second pair of dielectric materials is disposed adjacent to the second side of the ultrathin reflective layer, wherein the second pair includes a third layer of dielectric material and a fourth layer of a different dielectric material. The filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output that exhibits minimal angular dependence. The photovoltaic device is disposed adjacent to the color reflective filter. The photovoltaic device includes at least one photosensitive material.

[0023] In one aspect, the photovoltaic device has a power conversion efficiency greater than or equal to about 18%.

[0024] In one aspect, the angle-insensitive color photovoltaic device assembly of claim 13, wherein the photosensitive material comprises crystalline silicon (c-Si) material.

[0025] In one aspect, the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material.

[0026] In one aspect, the ultra-thin reflective layer has a thickness less than or equal to about 15 nm.

[0027] In one aspect, the reflected output having the second predetermined wavelength range is in the visible range and has a color selected from red, green, blue, and combinations thereof.

[0028] In one aspect, the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), titanium oxide (TiO2) and silicon dioxide (SiO2), zinc oxide (ZnO), hafnium oxide (HfO2), molybdenum trioxide (MoO3), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), tungsten trioxide (WO3), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and a polymer having a refractive index greater than or equal to about 1.6.

[0029] In one aspect, the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), zinc selenide (ZnSe), titanium oxide (TiO2) and silicon dioxide (SiO2).

[0030] In one aspect, the first layer comprises silicon dioxide (SiO2), the second layer comprises titanium oxide (TiO2), the third layer comprises titanium oxide (TiO2), and the fourth layer comprises silicon nitride (Si3N4).

[0031] In one aspect, the first layer comprises silicon nitride (Si3N4), the second layer comprises zinc selenide (ZnSe), the third layer comprises zinc selenide (ZnSe), and the fourth layer comprises silicon nitride (Si3N4).

[0032] In one aspect, the thickness of the first layer is greater than or equal to about 50 nm to less than or equal to about 300 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 50 nm to less than or equal to about 300 nm.

[0033] In one aspect, the reflective output having the second predetermined wavelength range exhibits a blue color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 50 nm to less than or equal to about 200 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 150 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 150 nm, and the thickness of the fourth layer is greater than or equal to about 50 nm to less than or equal to about 200 nm.

[0034] In one aspect, the reflective output having the second predetermined wavelength range exhibits a green color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 100 nm to less than or equal to about 200 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 100 nm to less than or equal to about 200 nm.

[0035] In one aspect, the reflective output having the second predetermined wavelength range exhibits a red color. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer is greater than or equal to about 100 nm to less than or equal to about 300 nm, the thickness of the second layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, the thickness of the third layer is greater than or equal to about 10 nm to less than or equal to about 200 nm, and the thickness of the fourth layer is greater than or equal to about 100 nm to less than or equal to about 300 nm.

[0036] In certain other variations, the present disclosure contemplates an active color reflective filter for use with a photovoltaic device. The filter includes an ultrathin reflective layer defining a first side and a second side. The active reflective color filter also includes a first transparent electrode having a first polarity and a second transparent electrode having a second polarity opposite to the first polarity. The active color reflective filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output.

[0037] In one aspect, the reflective output exhibits minimal angular dependence such that the second predetermined wavelength range varies by less than or equal to about 80 nm at incident angles of about 0° to about 60° relative to the active color reflective filter to form an angle-insensitive active reflective color filter.

[0038] In one aspect, the active color reflective filter further includes a first doped layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second doped layer disposed between the ultra-thin reflective layer and the second transparent electrode.

[0039] In one aspect, the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material. The first doped layer comprises an n-doped silicon oxide (SiO x The second doped layer comprises p-doped silicon oxide (SiO x ). The first transparent electrode and the second transparent electrode independently include a material selected from the group consisting of aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), indium zinc oxide (IZO), magnesium and gallium co-doped zinc oxide (MGZO), boron-doped zinc oxide (BZO), and combinations thereof.

[0040] In one aspect, the thickness of the first transparent electrode is greater than or equal to about 50 nm to less than or equal to about 200 nm. The thickness of the second transparent electrode is greater than or equal to about 750 nm to less than or equal to about 1.5 microns. The thickness of the first doped layer is greater than or equal to about 10 nm to less than or equal to about 20 nm. The thickness of the second doped layer is greater than or equal to about 5 nm to less than or equal to about 20 nm. The thickness of the ultra-thin reflective layer is greater than or equal to about 5 nm to less than or equal to about 55 nm.

[0041] The present disclosure also contemplates an angle-insensitive color photovoltaic device assembly including an active color reflective filter and a photovoltaic device. The active color reflective filter includes an ultra-thin reflective layer defining a first side and a second side. A first transparent electrode has a first polarity, and a second transparent electrode having a second polarity opposite to the first polarity is also included. The active color reflective filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output. The photovoltaic device is adjacent to the active color reflective filter. The photovoltaic device includes at least one photosensitive material.

[0042] In one aspect, the reflective output exhibits minimal angular dependence such that the second predetermined wavelength range varies by less than or equal to about 80 nm at incident angles of about 0° to about 60° relative to the active color reflective filter.

[0043] In one aspect, the first transparent electrode and the second transparent electrode comprise materials independently selected from indium tin oxide (ITO) and indium zinc oxide (IZO), the ultra-thin reflective layer comprises amorphous silicon (a-Si) material, and the photosensitive material includes crystalline silicon (c-Si).

[0044] In one aspect, the active color reflective filter further includes a first charge transport layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second charge transport layer disposed between the ultra-thin reflective layer and the second transparent electrode.

[0045] In one aspect, the active color reflective filter further includes a first doped layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second doped layer disposed between the ultra-thin reflective layer and the second transparent electrode.

[0046] 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

[0047] 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.

[0048] Figure 1 is a cross-sectional view of an angle-insensitive passive color reflective filter prepared according to certain aspects of the present disclosure.

[0049] Figure 2 According to some aspects of the present disclosure, Figure 1 Cross-sectional view of an angle-insensitive passive color reflective filter and an angle-insensitive color photovoltaic device assembly with an integrated photovoltaic device.

[0050] Figure 3 is a cross-sectional view of an angle-insensitive color photovoltaic device assembly incorporating an angle-insensitive active color reflective filter and an integrated photovoltaic device according to certain alternative aspects of the present disclosure.

[0051] Figure 4 Schematic diagram showing the setup for current density-voltage (JV) data acquisition of an angle-insensitive color photovoltaic device assembly with a passive color reflective filter and an integrated photovoltaic device. The insets at the upper left and lower right present the dimensions of the c-Si photovoltaic device / solar panel and the aluminum foil with an opening at the upper surface, respectively.

[0052] FIG5A to FIG5C. FIG5A shows a passive angle-insensitive color filter that reflects blue, according to certain aspects of the present disclosure. For a silicon solar cell, the reflectance peak intensity of the blue passive filter at a wavelength of 451 nm is about 40%. FIG5B shows simulated and measured reflectance and transmission spectra of the passive angle-insensitive color filter that reflects blue shown in FIG5A. FIG5C shows a graph of color coordinates from both simulated and measured reflectance spectra plotted on a CIE 1931 chromaticity diagram.

[0053] Figure 6 A diagram of the reflection spectrum of a blue structure with an intermediate semiconductor layer having the a-Si layer replaced by materials with different refractive indices ranging from 2.5 to 4.5 is shown.

[0054] Figures 7A to 7D. Figures 7A and 7B show graphical representations of simulated reflection and transmission spectra for green and red passive filters, respectively. Figures 7C and 7D show simulated angular behavior of passive green and red filters, respectively.

[0055] Figure 8 A graphical representation of the refractive index of Si3N4, TiO2, a-Si and SiO2 dielectric materials using a spectroscopic ellipsometer (M-2000, JA Woollam) is shown.

[0056] Figures 9A to 9C. Figures 9A and 9B show graphical representations of calculated and measured angle-resolved reflectance of a blue filter prepared according to certain aspects of the present disclosure under unpolarized light illumination. Figure 9C shows photographs of a fabricated blue filter taken under ambient light illumination with a black background at four different viewing angles, demonstrating that a stable blue color can be maintained over a wide range of angles.

[0057] Figures 10A-10B. Figure 10A shows a graphical representation of the normalized total phase shift calculated within each dielectric layer of a multilayer stack for a passive optical filter, indicating the location of the transmission FP resonance that causes enhanced transmission. Figure 10B shows a graphical representation of the simulated reflectance spectrum of the filter structure with the subsequent addition of those 4 dielectric layers.

[0058] Fig.11 Optical admittance plots of an angle-insensitive passive color reflective filter according to certain aspects of the present disclosure at wavelengths of 300 nm, 400 nm, 450 nm, 600 nm, 800 nm, and 1000 nm, respectively, are shown.

[0059] Fig.12 The current density-voltage (JV) characteristics of a photovoltaic device assembly incorporating a blue angle-insensitive passive reflective filter under AM1.5 illumination (100 mWcm) are shown compared to the original c-Si photovoltaic cell without a reflective filter. -2 ) is a graphical representation of the measured current density-voltage (JV) characteristics under .

[0060] Figures 13A to 13D. Figure 13A shows a schematic diagram of a blue reflecting passive angle-insensitive color filter with enhanced reflection prepared according to certain aspects of the present disclosure. Figure 13B shows the reflection and transmission spectra of the new blue passive filter of Figure 13A. Figure 13C shows optical images of the fabricated sample at multiple viewing angles, showing large angle insensitivity. Figure 13D shows the measured JV performance of an angle-insensitive color photovoltaic device assembly combining a blue reflecting filter and a photovoltaic device under AM1.5 illumination compared to the JV performance of a pristine c-Si photovoltaic cell without the filter.

[0061] Figures 14A to 14D illustrate active angle-insensitive color photovoltaic device assemblies prepared according to certain aspects of the present disclosure. Figure 14A illustrates a cross-sectional view of an active angle-insensitive color photovoltaic device assembly having an angle-insensitive active color reflective filter and an integrated photovoltaic device according to certain alternative aspects of the present disclosure. In Figure 14B, a picture of a green solar cell is shown. Figures 14C to 14D illustrate the optical and electrical performance of the active angle-insensitive color photovoltaic device assembly, respectively.

[0062] Fig.15 Shown are simulated optical performances of active angle-insensitive photovoltaic device assemblies including a-Si solar cells of different RGB colors prepared according to certain aspects of the present disclosure.

[0063] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0064] Exemplary embodiments are provided so that the present disclosure will be comprehensive, and the scope will be fully conveyed to those skilled in the art. Many specific details are set forth, such as examples of specific compositions, components, devices and methods, to provide a thorough understanding of the embodiments of the present disclosure. It is apparent to those skilled in the art that specific details need not be adopted, and exemplary embodiments can be implemented in many different forms, and neither should be construed as limiting the scope of the present disclosure. In some exemplary embodiments, known methods, known device structures and known technologies are not described in detail.

[0065] The terms used herein are only used for the purpose of describing specific exemplary embodiments, and are not intended to be restrictive. As used herein, unless the context clearly indicates otherwise, the singular form may also be intended to include the plural form. The terms "comprises", "comprising", "containing" and "having" are inclusive, and therefore specify the presence of the 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 groups thereof. Although the open term "comprising" is understood as a non-limiting term for describing and claiming the various embodiments set forth herein, in some aspects, the term may be alternatively understood as a more restrictive and restrictive term, such as "consisting of" or "consisting essentially of". Thus, for any given embodiment stating compositions, materials, components, elements, features, integers, operations, and / or process steps, the present disclosure also specifically includes embodiments consisting of or consisting essentially of such stated compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of "consisting of", alternative embodiments exclude 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 properties are excluded from such embodiments, but any compositions, materials, components, elements, features, integers, operations, and / or process steps that do not materially affect the basic and novel properties may be included in the embodiments.

[0066] Any method steps, processes, and operations described herein should not be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically indicated as an order of performance. It should also be understood that additional or alternative steps may be utilized unless otherwise indicated.

[0067] When a component, element or layer is referred to as being "on" another element or layer, "engaged to" another element or layer, "connected to" another element or layer, or "coupled to" another element or layer, it may be directly on another component, element or layer, directly engaged to another component, element or layer, directly connected to another component, element or layer, or directly coupled to another component, element or layer, or there may be an intermediate element or layer. In contrast, when an element is referred to as being "directly on" another element or layer, "directly engaged to" another element or layer, "directly connected to" another element or layer, or "directly coupled to" another element or layer, there may be no intermediate element or layer. Other words used to describe the relationship between elements (e.g., "between" and "directly between", "adjacent" and "directly adjacent", etc.) should be interpreted in a similar manner. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0068] Although the term first, second, third etc. can be used to describe multiple steps, elements, components, regions, layers and / or parts in this article, unless otherwise noted, these steps, elements, components, regions, layers and / or parts should not be limited 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, otherwise when used in this article, terms such as "first", "second" and other numerical terms do not mean order or sequence. Therefore, without departing from the teaching of exemplary embodiments, the first step, element, component, region, layer or part discussed below can be referred to as the second step, element, component, region, layer or part.

[0069] In this document, spatially or temporally relative terms such as "before", "after", "inside", "outside", "under", "below", "lower", "above", "upper", etc. may be used to facilitate the description of the relationship of one element or feature to another element or feature as shown in the drawings. Spatially or temporally relative terms may be intended to include different orientations of a device or system in use or operation in addition to the orientation depicted in the drawings.

[0070] Throughout this disclosure, numerical values ​​represent approximate measurements or are limited to a range of minor deviations that include a given value, as well as embodiments that approximately have the value and precisely have the value. Except for the working examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified by the term "about" in all cases, regardless of whether "about" actually appears before the numerical value. "About" means that the numerical value allows some slight imprecision (some of which are close to the precision in the numerical value; approximately or reasonably close to the numerical value; almost). If the imprecision provided by "about" is not otherwise understood in this art in the usual sense, then "about" as used herein at least represents the variation that can be caused by the general method of measuring and using such parameters. For example, "about" can include the following variations: 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%.

[0071] Unless otherwise indicated, compositions are given in mass / weight percentages.

[0072] Furthermore, disclosure of ranges includes disclosure of all values ​​within the entire range and further divided ranges, including endpoints and sub-ranges given for the ranges.

[0073] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0074] In various aspects, the present disclosure contemplates a high-efficiency color solar cell assembly comprising both a passive reflective color filter combined with a photovoltaic device. For example, as described herein, the present disclosure contemplates an angle-insensitive color photovoltaic device assembly comprising a color reflective filter and a photovoltaic device. As will be further described below, the photovoltaic device is adjacent to one side of the color reflective filter and optionally in contact with one side of the color reflective filter.

[0075] Figure 1A passive angle-insensitive color filter 50 according to certain aspects of the present disclosure is shown. The filter 50 has a plurality of layers forming a multilayer stack or assembly. Thus, the filter 50 includes an ultra-thin reflective layer 52 defining a first side 54 and a second side 56. The ultra-thin reflective layer 52 may be a high refractive index material, a semiconductor material, or a metal layer. In certain aspects, the ultra-thin reflective layer 52 comprises an amorphous silicon (a-Si) material. Amorphous silicon has a refractive index that increases from about 3.3 to about 5.0 when the wavelength increases from 300 nm to about 400 nm, and decreases from about 5.0 to about 3.5 when the wavelength increases from about 400 nm to 1100 nm, and decreases from about 3.5 to 0 when the imaginary part increases from about 300 nm to 1100 nm. "Ultra-thin" means that the thickness of the layer is less than or equal to about 20 nm. In certain variations, the thickness of the ultra-thin reflective layer 52 is less than or equal to about 15 nm. In some variations, the thickness of the ultra-thin reflective layer 52 is greater than or equal to about 5 nm to less than or equal to about 12 nm. In one aspect, the thickness of the ultra-thin reflective layer 52 is greater than or equal to about 5 nm to less than or equal to about 10 nm. In another variation, the thickness of the ultra-thin reflective layer 52 is greater than or equal to about 10 nm to less than or equal to about 12 nm.

[0076] The filter 50 includes a transparent first pair 60 of dielectric materials adjacent to a first side 54 of an ultra-thin reflective layer 52. The first pair 60 includes a first layer 70 of a dielectric material and a second layer 72 of a different dielectric material. The filter 50 also includes a transparent second pair 62 of dielectric materials adjacent to a second side 56 of the ultra-thin reflective layer 52. The second pair 62 includes a third layer 74 of a dielectric material and a fourth layer 76 of a different dielectric material. The second pair 62 of dielectric materials are disposed on a substrate 78. The substrate 78 may be formed of a material such as silicon dioxide (e.g., fused silica or glass), quartz, and a polymer (e.g., polycarbonate or acrylate) that is transparent to certain predetermined wavelengths of light. It should be noted that in alternative variations, additional layers or components may be included in the filter 50. As an example, although not shown, an index-matching layer may be included on the side of the substrate 78 opposite to the fourth layer 76.

[0077] The dielectric materials used for layers 70 to 74 can each be independently selected from silicon nitride (Si3N4), titanium oxide (TiO2) and silicon dioxide (SiO2), zinc oxide (ZnO), hafnium oxide (HfO2), molybdenum trioxide (MoO3), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), tungsten trioxide (WO3), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and / or polymers having similar suitable refractive indices. In one variation, the dielectric material selected for forming each of the first layer 70, the second layer 72, the third layer 74, and the fourth layer 76 is independently selected from silicon nitride (Si3N4), zinc selenide (ZnSe), titanium oxide (TiO2), and silicon dioxide (SiO2). In some aspects, one or more of layers 70 to 74 may be a high refractive index material having a refractive index greater than or equal to about 1.6, optionally greater than or equal to about 1.7, optionally greater than or equal to about 1.8, optionally greater than or equal to about 1.9, optionally greater than or equal to about 2, optionally greater than or equal to about 2.1, and in some variations, optionally greater than or equal to about 2.2. As non-limiting examples, suitable high refractive index materials for use in accordance with the present disclosure include silicon nitride (Si3N4) having a refractive index of 2.0, titanium oxide (TiO2) having a refractive index of about 2.2, and zinc selenide (ZnSe) having a refractive index of about 2.6.

[0078] Other envisioned high index materials are optical metamaterials. Metamaterials are synthetic materials designed to have properties based on their structure rather than the composition of the material itself, which are typically anisotropic and inhomogeneous, by using small inhomogeneities to produce effective macroscopic behavior. Many such optical metamaterials have high refractive indices, or can be designed to have high refractive indices while still having minimal absorption in a target spectral range, for example, metamaterials can have a refractive index greater than or equal to about 2; optionally greater than or equal to about 3, optionally greater than or equal to 3.5, optionally greater than or equal to about 4, and in some aspects, optionally up to 5 or more than 5. In certain additional embodiments described below, such metamaterials can be used in alternative optical filter device embodiments to provide color filtering with minimal angular dependence.

[0079] In some aspects, the first layer 70 comprises silicon dioxide (SiO2), the second layer 72 comprises titanium oxide (TiO2), the third layer 74 comprises titanium oxide (TiO2), and the fourth layer 76 comprises silicon nitride (Si3N4). In certain other aspects, the first layer 70 comprises silicon nitride (Si3N4), the second layer 72 comprises zinc selenide (ZnSe), the third layer 74 comprises zinc selenide (ZnSe), and the fourth layer 76 comprises silicon nitride (Si3N4). In certain aspects, the thickness of the first layer 70 is greater than or equal to about 50nm to less than or equal to about 300nm, and in certain variations, optionally greater than or equal to about 145nm to less than or equal to about 245nm. The thickness of the second layer 72 can be greater than or equal to about 10nm to less than or equal to about 200nm, and in certain variations, optionally greater than or equal to about 100nm to less than or equal to about 195nm. The thickness of the third layer 74 can be greater than or equal to about 10 nm to less than or equal to about 200 nm, and in some variations, optionally greater than or equal to about 25 nm to less than or equal to about 75 nm. The thickness of the fourth layer 76 is greater than or equal to about 50 nm to less than or equal to about 300 nm, and in some variations, optionally greater than or equal to about 100 nm to less than or equal to about 155 nm.

[0080] like Figure 1 As shown, an electromagnetic wave 80 (e.g., sunlight) is directed toward the optical filter 50. In various aspects, the optical filter 50 is capable of transmitting a first portion of the electromagnetic wave 80 having a first predetermined wavelength range, as indicated by arrow 82. The optical filter 50 also reflects a second portion of the electromagnetic spectrum / electromagnetic wave 80 having a second predetermined wavelength range to produce a reflected output 84 that exhibits minimal angular dependence relative to an incident angle or viewing angle 86 from which the optical filter 50 can be seen or observed (e.g., by a person or machine). Figure 1 As shown, viewing angle 86 is 90°, but may vary based on the viewing position anywhere from greater than 0° to less than 180° (eg, ±90°).

[0081] Silicon photovoltaic panels respond to light with wavelengths in the range of about 300nm to 1100nm. Particularly suitable ultraviolet, visible and infrared electromagnetic radiation include ultraviolet radiation from about 300nm to about 390nm, visible light from about 390nm to about 750nm, and infrared radiation (IR) (including near infrared (NIR) from about 0.75μm to about 1.4μm). In the visible range of electromagnetic radiation, wavelengths in the range of about 625nm to 740nm are red; orange at about 590nm to about 625nm; yellow at about 565nm to about 590nm; green at about 520nm to about 565nm; blue or cyan at about 500nm to about 520nm; blue or indigo at about 435nm to about 500nm; violet at about 380nm to about 435nm. Notably, as used herein, blue can include blue / cyan, blue / indigo and violet.

[0082] In some embodiments, the reflected output 84 has a predetermined wavelength range produced by the filter 50 in the visible light range, which can include colors selected from red, green, blue, and combinations thereof. In some aspects, the reflected output 84 of electromagnetic radiation can have a wavelength in the following ranges: for red, a range of greater than or equal to about 625nm to less than or equal to about 740nm; for green, a range of greater than or equal to about 520nm to less than or equal to about 565nm; for blue or cyan, a range of greater than or equal to about 500nm to less than or equal to about 520nm, and for blue or indigo, a range of greater than or equal to about 435nm to less than or equal to about 500nm. In addition, in some aspects, the reflected light can be out of the spectrum or a mixture of several different wavelengths. For example, magenta is an out of the spectrum mixture of red (625nm to 740nm) and blue (435nm to 500nm) wavelengths.

[0083] In one variation, the angle-insensitive color filter 50 has a reflective output 84 having a predetermined wavelength range corresponding to the blue color, wherein the thickness of the ultra-thin reflective layer 52 is greater than or equal to about 5 nm to less than or equal to about 12 nm, the thickness of the first layer 70 is greater than or equal to about 50 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 145 nm to less than or equal to about 170 nm. The thickness of the second layer 72 is greater than or equal to about 10 nm to less than or equal to about 150 nm, and optionally greater than or equal to about 100 nm to less than or equal to about 120 nm. The thickness of the third layer 74 is greater than or equal to about 10 nm to less than or equal to about 150 nm, and optionally greater than or equal to about 25 nm to less than or equal to about 50 nm. The thickness of the fourth layer 76 is greater than or equal to about 10 nm to less than or equal to about 150 nm, and optionally greater than or equal to about 100 nm to less than or equal to about 120 nm.

[0084] In certain other variations, the angle-insensitive color filter 50 has a reflective output 84 having a predetermined wavelength range corresponding to the green color, wherein the ultra-thin reflective layer 52 has a thickness of greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer 70 is greater than or equal to about 100 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 185 nm to less than or equal to about 195 nm. The thickness of the second layer 72 is greater than or equal to about 10 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 145 nm to less than or equal to about 155 nm. The thickness of the third layer 74 is greater than or equal to about 10 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 35 nm to less than or equal to about 45 nm. The thickness of the fourth layer 76 is greater than or equal to about 100 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 135 nm to less than or equal to about 145 nm.

[0085] In yet other variations, the angle-insensitive color filter 50 has a reflective output 84 having a predetermined wavelength range corresponding to red, wherein the thickness of the ultra-thin reflective layer 52 is greater than or equal to about 5 nm to less than or equal to about 12 nm. The thickness of the first layer 70 is greater than or equal to about 100 nm to less than or equal to about 300 nm, and optionally greater than or equal to about 235 nm to less than or equal to about 245 nm. The thickness of the second layer 72 is greater than or equal to about 10 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 185 nm to less than or equal to about 195 nm. The thickness of the third layer 74 is greater than or equal to about 10 nm to less than or equal to about 200 nm, and optionally greater than or equal to about 65 nm to less than or equal to about 75 nm. The thickness of the fourth layer 76 is greater than or equal to about 100 nm to less than or equal to about 300 nm, and optionally greater than or equal to about 145 nm to less than or equal to about 155 nm.

[0086] In certain aspects, the passive angle-insensitive color filter 50 exhibits minimal angular dependence, which corresponds to a reflective output 84 having a second predetermined wavelength range that varies by less than or equal to about 80 nm, optionally less than or equal to 70 nm, optionally less than or equal to 60 nm when comparing the difference between a first wavelength at an incident angle or viewing angle of 0° and a second wavelength at an incident angle of 60°. Minimum deviation in reflective output can be expressed as minimal angular dependence. In certain particularly advantageous variations, the filter 50 has minimal angular dependence and is capable of producing a reflective output having a predetermined wavelength range (e.g., having a wavelength shift): when the filter is viewed from an angle of incidence of 0° to 60°, the deviation is less than or equal to 50 nm; optionally less than or equal to about 45 nm; optionally less than or equal to 40 nm; optionally less than or equal to 35 nm; optionally less than or equal to 30 nm based on the range of possible angles of incidence (when comparing the difference between a first wavelength of interest viewed at an angle of incidence of 0° and a second wavelength viewed at an angle of incidence or viewing angle of 60°). In certain aspects, the passive angularly insensitive color filter 50 has a non-iridescent appearance at the above-mentioned minimum wavelength variation up to ±60°.

[0087] Figure 2 Shown include Figure 1 The colored reflective filter 50 and the angle-insensitive colored photovoltaic device assembly 90 of the photovoltaic assembly 100. For simplicity, Figure 1 The above features and details in the context of will not be repeated here. The exemplary photovoltaic device assembly 100 has a photovoltaic cell 110 that may include a layer of photosensitive material. In certain variations, at least one photosensitive layer 114 comprises a crystalline silicon (c-Si) material. Thus, the photovoltaic cell may include a crystalline silicon (c-Si) panel; a back-contact photovoltaic cell; or a photovoltaic cell having a first electrode having a first polarity, a second electrode having a polarity opposite to the first electrode, and at least one photosensitive material layer (e.g., comprising c-Si) disposed between the first electrode and the second electrode. The photovoltaic assembly 100 may also include additional layers, such as a protective layer or an encapsulation layer, sandwiching the photovoltaic cell 110. Thus, the first layer 112 of the photovoltaic assembly 100 is disposed between the substrate 78 of the color reflective filter 50 and the photovoltaic cell 110, while there is a second layer 114 on the opposite side of the photovoltaic cell. The second layer 114 is disposed on the backplane 116. The first layer and the second layer may be formed of a material (such as ethylene vinyl acetate (EVA) as an example) that is transparent to light having a predetermined wavelength range that is expected to enter photovoltaic cell 110. Backsheet 116 may be formed of materials such as polyethylene terephthalate (PET), aluminum, etc. It should be noted that, although not shown, additional types of photovoltaic devices including other layers or components may be included in exemplary photovoltaic assembly 100.

[0088] As in Figure 1 As noted in the context of , the filter 50 is capable of transmitting a first portion of an electromagnetic wave 80 having a first predetermined wavelength range directed to the angle-insensitive color photovoltaic device assembly 90. The transmitted electromagnetic energy is indicated by arrow 82. Thus, the transmitted electromagnetic energy 82 passes through the filter 50 and enters the photovoltaic device 100. As described above, the filter 50 reflects a second portion of the electromagnetic spectrum / electromagnetic wave 80 having a second predetermined wavelength range to produce a reflected output 84. Since most of the transmitted electromagnetic energy 82 enters the photovoltaic device 100, the angle-insensitive color photovoltaic device assembly 90 can produce a power conversion efficiency (PCE) greater than or equal to about 15%, optionally greater than or equal to about 16%, optionally greater than or equal to about 17%, and in some aspects, optionally greater than or equal to about 18%.

[0089] Thus, in certain variations, the present disclosure provides an assembly including a PV device and a passive color filter having a novel tandem configuration, wherein the PV device may include a crystalline silicon (c-Si) PV panel, wherein the passive color filter exhibits angle insensitivity while reflecting a desired one or more colors for decorative or aesthetic appearance. As described above, the passive reflective filter may include five layers, wherein a semiconductor (e.g., a-Si) may be sandwiched between two pairs / two stacks of transparent dielectrics, which may transmit a large portion of the solar spectrum to be harvested by the c-Si PV module below by adopting a gradient index profile, thereby achieving overall high efficiency. In this manner, an angle-robust / insensitive color solar cell / photovoltaic device assembly having high efficiency (e.g., greater than or equal to about 18% in certain variations) is provided by integrating a crystalline silicon (c-Si) solar panel / PV device with a passive color filter disposed atop the PV device. Furthermore, due to the high refractive index of the semiconductor layers (eg, a-Si) involved in the color filter module, the angle-insensitive color photovoltaic device assembly exhibits a non-iridescent appearance up to ±60° with high brightness (about 55% peak reflection).

[0090] Thus, the present disclosure provides a passive angle-insensitive photovoltaic device assembly comprising a passive angle-insensitive color filter having a significantly reduced number of layers compared to one-dimensional (1D) photonic crystals (PCs) that typically include at least ten different layers, while also overcoming the angle sensitivity and low efficiency issues of typical color solar cells. In this manner, the passive angle-insensitive photovoltaic device assembly of the present invention has great potential for a variety of applications in which photovoltaic devices can be employed, including industries such as buildings, automobiles, ships, aviation, and agriculture, including solar energy collection surfaces / coatings, innovative solar buildings / building integrated photovoltaics (BIPV), and solar vehicles (e.g., cars, motorcycles, boats). The present technology can be implemented on a large scale and easily applied to mass production.

[0091] In such Figure 3 In some alternative variations shown, an angle-insensitive color photovoltaic device assembly 150 is shown, which includes an active color reflective assembly 152 and a photovoltaic device 100 (such as Figure 2 For simplicity, Figure 2 The commonality of the above features and details in the context of will not be repeated here. As a non-limiting example, the exemplary photovoltaic device assembly 100 has a photovoltaic cell 110, which, although not shown, can have a first electrode having a first polarity, a second electrode having a polarity opposite to the first electrode, and at least one photosensitive material layer (e.g., comprising c-Si) disposed between the first electrode and the second electrode. The first layer 112 and the second layer 114 sandwich the photovoltaic cell 110. As previously described in Figure 2 , the second layer is disposed on the backplane 116. The active color reflective assembly 152 is improved from the passive angle-insensitive color filter 50 to replace at least some dielectric materials with transparent electrodes. Therefore, the active color reflective assembly 152 has a third electrode 160 with a third polarity and a fourth electrode 162 with a fourth polarity opposite to the third polarity. An ultra-thin reflective layer 170 is disposed between the third electrode 160 and the fourth electrode 162. The ultra-thin reflective layer 170 can be a semiconductor and can have a high refractive index, for example, containing an amorphous silicon (a-Si) material. The third electrode 160 and the fourth electrode 162 can be formed of a conductive and transparent material, such as indium tin oxide (ITO) and indium zinc oxide (IZO). It should be noted that, although not shown, additional layers or components (e.g., such as terminals) may be included in the exemplary angle-insensitive color photovoltaic device assembly 150.

[0092] As in Figure 1 and Figure 2As noted in the context of FIG. 1 , the angle-insensitive color photovoltaic device assembly 150 is capable of transmitting a first portion of an electromagnetic wave 80 having a first predetermined wavelength range directed toward the photovoltaic device assembly 150. The transmitted electromagnetic energy is indicated by arrow 82. Thus, the transmitted electromagnetic energy 82 passes through the active color reflective assembly 152 and enters the photovoltaic device 100. As with the previous embodiments, the active color reflective assembly 152 reflects a second portion of the electromagnetic spectrum / electromagnetic wave 80 having a second predetermined wavelength range to produce a reflective output 84 having the above-described characteristics including angle insensitivity and brightness. In this manner, in certain embodiments, the angle-insensitive color photovoltaic device assembly 150 having a design with a first electrode (not shown), a second electrode (not shown), a third electrode 160, and a fourth electrode 162 can form a four-terminal photovoltaic device (terminals not shown, but electrically connected to each corresponding electrode) that produces additional photon-to-current conversion in both the active color reflective assembly 152 and the photovoltaic device 100. Thus, the angle-insensitive color photovoltaic device assembly 150 exhibits angle-insensitivity and reflectivity of a predetermined color, but is believed to be able to further enhance the PCE of the photovoltaic device assembly 150 beyond the PCE of the angle-insensitive color photovoltaic device assembly 90 combined with the passive angle-insensitive color filter 50 described above.

[0093] In another variation shown in FIG. 14A , the angle-insensitive color photovoltaic device assembly 200 includes an active color reflective assembly 210 that defines both the filter and the photovoltaic device. Figures 1 to 3 The commonality of the above features and details in the context of will not be repeated here. The exemplary photovoltaic device assembly 200 has a first electrode 220 having a first polarity, a second electrode 222 having a polarity opposite to the first electrode 220. The first doped layer 230 is a charge transport layer disposed adjacent to the first electrode 220 and serving as an electron hole transport layer, and the second doped layer 232 is a charge transport layer disposed adjacent to the second electrode 222 and serving as an electron transport layer.

[0094] The first electrode 220 and the second electrode 222 may be formed of a transparent conductive material such as aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), indium zinc oxide (IZO), magnesium and gallium co-doped zinc oxide (MGZO), boron-doped zinc oxide (BZO), combinations thereof, and the like. In one variation, the first electrode 220 includes indium tin oxide (ITO), which may be formed via an electron beam deposition process. The second electrode 222 may be formed of aluminum-doped zinc oxide (AZO). Aluminum-doped zinc oxide (AZO) and indium tin oxide (ITO) may be used as anodes and cathodes, respectively, due to their transparency and compatibility with the corresponding interface layers. Although not shown, it should be noted that other transparent electrodes including magnesium and gallium co-doped zinc oxide (MGZO), boron-doped zinc oxide (BZO), and the like may also be used if another suitable transport layer is employed.

[0095] As described above, the first doping layer 230 may be a charge (eg, electron) transport layer. For example, the first doping layer 230 may be a material based on doped n-type silicon, such as n-type silicon oxide (SiO x As an example, the silicon oxide (SiO x ) material contains doping atoms (e.g., phosphorus (P)) that have one or more electrons in their external energy level than silicon has to produce doped n-type silicon oxide. The electrons are donated when excited. As shown, the first doped layer 230 is a single layer, although it can have multiple layers. In one variation, the n-SiO x The thickness of the first doping layer 230 may be about 15 nm.

[0096] The second doping layer 232 may be a charge (eg, hole) transport layer. For example, the second doping layer 232 may be a material based on doped p-type silicon, such as p-type silicon oxide (SiO x As an example, the silicon oxide (SiO x ) material contains dopant atoms (e.g., boron (B) or gallium (Ga)) that have one or more fewer electrons in their outer energy levels than silicon has to produce doped p-type silicon oxide. Because the dopant has at least one less electron than is required to form bonds with surrounding silicon atoms, electron vacancies or positively charged holes are created when excited. As shown, the second doped layer 232 is a single layer, although it can have multiple layers. In one variation, the p-SiO x The thickness of the second doping layer 232 may be about 10 nm.

[0097] The ultra-thin reflective layer 240 is disposed between the first doped layer 230 and the second doped layer 232. The ultra-thin reflective layer 240 may be a semiconductor and may have a high refractive index, for example, comprising an amorphous silicon (a-Si) material. The ultra-thin reflective layer 240 may be formed of the material and have any thickness described above. In one example, the ultra-thin reflective layer 240 comprises amorphous silicon (a-Si) and may be about 11 nm thick.

[0098] In this manner, the first electrode 220, the first doped layer 230, the ultra-thin reflective layer 240, the second doped layer 232, and the second electrode 222 define an active color reflective assembly 210 including a photovoltaic cell, thereby defining an angle-insensitive color photovoltaic device assembly 200. As previously described in Figure 2 As described in the context of , the second electrode 222 is disposed on a substrate or backplane 242. As an example, the backplane 242 can be formed of a glass material. The active color reflective assembly 210 is improved from the passive angle-insensitive color filter 50 to replace at least some dielectric materials with a transparent electrode and an n-doped layer or a p-doped layer.

[0099] It should be noted that, although not shown, additional layers or components (such as terminals, for example) may be included in the exemplary angle-insensitive color photovoltaic device assembly 200 .

[0100] As in Figures 1 to 3As noted in the context of FIG. 1 , the active angle-insensitive color photovoltaic device assembly 200 is capable of transmitting a first portion of an electromagnetic wave 80 having a first predetermined wavelength range directed toward the photovoltaic device assembly 200. The transmitted electromagnetic energy is indicated by arrow 82. Thus, the transmitted electromagnetic energy 82 passes through and enters the active color reflective assembly 210 defining the photovoltaic device. Like the previous embodiments, the active color reflective assembly 210 reflects a second portion of the electromagnetic spectrum / electromagnetic wave 80 having a second predetermined wavelength range to produce a reflective output 84 having the above-described characteristics including angle insensitivity and brightness. In this manner, in certain embodiments, the active angle-insensitive color photovoltaic device assembly 200 having a design with a first electrode 220 and a second electrode 222 defines a photovoltaic device (terminals not shown, but electrically connected to each corresponding electrode) that produces additional conversion of photons to current in the active color reflective assembly / photovoltaic device 210. Thus, the active angle-insensitive color photovoltaic device assembly 210 exhibits angle insensitivity and reflectivity of a predetermined color, but it is also capable of enhancing the PCE of the integrated photovoltaic device assembly or auxiliary photovoltaic assembly beyond the PCE described in the context of an angle-insensitive color photovoltaic device assembly with a passive angle-insensitive color filter. Thus, the angle-insensitive color photovoltaic device assembly 200 includes an active color reflective assembly 210 (e.g., such as an active color reflective assembly 210) that can be coupled to another photovoltaic device disposed below the active color reflective assembly 210. Figure 3 shown).

[0101] In the case where the angle-insensitive color photovoltaic device assembly 200 includes an active color reflective assembly 210, the dielectric material pair (e.g., ZnSe and Si3N4) is replaced by a suitable hole / electron transport layer and a transparent electrode so that the device can be suitable for an active solar cell. Here, the first doped layer 230 and the second doped layer 232 (i.e., n-SiO2 as an electron transport layer and a hole transport layer, respectively) are selected in consideration of the substantially perfect band orientation of the first doped layer 230 and the second doped layer 232 with the a-Si in the ultra-thin reflective layer 240. x and p-SiO x ). Aluminum-doped zinc oxide (AZO) and indium tin oxide (ITO) are used as transparent anode (e.g., first electrode 220) and cathode (e.g., second electrode 222), respectively, due to their transparency and compatibility with the corresponding interface layers. The thickness of each layer is carefully selected to achieve optimal electrical performance.

[0102] As a non-limiting example, the thickness of the first electrode 220 can be greater than or equal to about 50 nm to less than or equal to about 200 nm, optionally greater than or equal to about 75 nm to less than or equal to about 170 nm. The thickness of the second electrode 222 can be greater than or equal to about 750 nm to less than or equal to about 1,500 nm (1.5 μm), optionally about 1,000 nm (1 μm). The thickness of the first doping layer 230 or transport layer can be greater than or equal to about 10 nm to less than or equal to about 20 nm, optionally greater than or equal to about 15 nm to less than or equal to about 19 nm. The thickness of the second doping layer 232 or transport layer can be greater than or equal to about 5 nm to less than or equal to about 20 nm, optionally greater than or equal to about 10 nm to less than or equal to about 19 nm. The thickness of the ultra-thin reflective layer 240 may be greater than or equal to about 5 nm to less than or equal to about 55 nm, optionally greater than or equal to about 10 nm to less than or equal to about 55 nm, and optionally greater than or equal to about 10 nm to less than or equal to about 13 nm.

[0103] In one variation, as shown in FIG. 14A , the electron beam deposited ITO first electrode 220 has a thickness of about 75 nm and has an n-SiO x The first doping layer 230 has a thickness of about 15 nm, the ultra-thin reflective layer 240 of a-Si has a thickness of about 11 nm, and the p-SiO x The second doping layer 232 and the second electrode 222 have a thickness of about 1 micron.

[0104] Various embodiments of the present technology can be further understood through the specific examples included herein. The specific examples are provided for the purpose of illustrating how to make and use the compositions, devices and methods according to the present teachings, and unless otherwise explicitly stated, it is not intended to represent that a given embodiment of the present invention has or has not been made or tested.

[0105] Example

[0106] Passive angle-insensitive color filters are fabricated by depositing layers on a fused silica substrate. TiO2 was deposited at a rate of 1.5 %. Plasma enhanced chemical vapor deposition (PECVD) was used at 260°C, 260°C and 200°C respectively. and Si3N4, a-Si and SiO2 are deposited at a rate of

[0107] Optical simulations for calculating the spectral reflection and transmission, angle-resolved spectra, electric field intensity distribution and net phase shift within each dielectric layer are based on the transfer matrix method, where the refractive index of the materials is calibrated using a spectroscopic ellipsometer (M-2000, JA Woollam).

[0108] Optical and electrical characterizations were performed as follows. Reflection spectra at normal incidence were obtained using a thin film measurement instrument (F20, Filmetrics) with an integrated spectrometer and white light source. Angular resolved reflection spectra from 45° to 60° and transmission spectra at normal incidence were measured using a spectroscopic ellipsometer (M-2000, JA Woollam).

[0109] Using aluminum foil to cover commercial back-contact c-Si solar panels (approximately 125mm 2 , Sunpower Corporation) surface, 25mm 2 Passive filter leaves 22mm in the center 2 Then, by connecting MP-160 (EKO Instruments) to the electrode ( Figure 4 The detailed device is shown), simulating sunlight at AM1.5 (100mWcm -2 ) to record the current density-voltage (JV) performance of the integrated color solar cells under illumination.

[0110] Figures 5A to 5D illustrate an angularly robust passive filter and its performance according to certain aspects of the present disclosure. The angle-insensitive passive filter is capable of producing a unique reflective color of blue, as well as an overall high transmission using optical interference within only 5 thin layers. As shown in Figure 5A, an ultra-thin a-Si layer (about 5nm) is sandwiched between two stacks or pairs of layers of transparent dielectrics (silicon nitride (Si3N4) / titanium dioxide (TiO2) and TiO2 / silicon dioxide (SiO2)) to form a graded index profile. This design allows significant transmission across the entire solar spectrum to be harvested by the photovoltaic device below that incorporates a crystalline silicon (c-Si) photosensitive layer (as shown in Figure 5B). The high refractive index of a-Si used in the angle-insensitive passive filter directly contributes to the final strong reflection of the designed color, with the peak reflection at 452nm being about 40%, which is in the Figure 6 Further described in .

[0111] Figure 6The reflectance spectra of structures using materials with different refractive indices as the intermediate layers are compared. Here, blue is used as an example to illustrate the working principle, and the corresponding thicknesses of Si3N4, bottom TiO2, top TiO2 and SiO2 are 100nm, 50nm, 120nm and 150nm respectively. Alternatively, by adjusting the thickness of these 4 dielectric layers while keeping the a-Si thickness at 5nm, green and red reflectance outputs can be easily achieved.

[0112] The thickness of the remaining layers in the multilayer stack remains the same in each case. Except a-Si (n=4.80+i0.95, the peak intensity at 452nm is about 40%), the scattering of all these materials is ignored. Obviously, the peak reflection intensity remains at about 450nm and increases with the refractive index: 26% (n=2.5) at 449nm, 29% (n=3.0) at 449nm, 31% (n=3.5) at 450nm, 35% (n=4.0) at 450nm, 38% (n=4.5) at 451nm, thereby confirming that the high reflection is attributed to the high refractive index of the intermediate layer.

[0113] Table 1 lists the thickness of different dielectric layers in the passive filter structure for each RGB color.

[0114] Table 1

[0115]

[0116] Figures 7A to 7D provide simulated reflection and transmission spectra and simulated angular behavior for filters reflecting green (Figures 7A and 7C) and red (Figures 7B and 7D). Considering that the high refractive index ultra-thin a-Si semiconductor layer is the main factor in the reflection peak, and the real refractive index of a-Si decreases at longer wavelengths, when a-Si is fixed at a thickness of 5nm, the peak reflection intensity for green (37% at 538nm) and the peak reflection intensity for red (32% at 666nm) are correspondingly smaller. The inset is a visualized reflection color for each filter, showing different green and red colors. Table 1 summarizes the dimensions of each layer. In Figures 7C and 7D, the simulated angular behavior of the green and red filters is shown, where the flat scattering spectra indicate the significant angular robustness required for decorative applications.

[0117] The refractive indices of all materials (a-Si, Si3N4, TiO2 and SiO2) were characterized using a spectroscopic ellipsometer (M-2000, JA Woollam) and are provided in Figure 8 middle.

[0118] From Figure 5B, an excellent agreement between the simulation results and the measured results can be observed, although the slightly higher transmission observed in the measurements from 400nm to 600nm than calculated can be attributed to the difference in the refractive index of the material calibrated for the simulation and the refractive index of the fabricated device. It is worth noting that if an additional refractive index matching layer is introduced when integrated with a c-Si photovoltaic module, the "background" reflection of about 3.5% (i.e., the weak reflection outside the 600nm wavelength in the figure) caused by the back reflection of the fused silica substrate can be suppressed, which will further improve the reflection color purity and the PCE of the entire device with the enhanced absorption of the c-Si panel / PV device below. In Figure 5C, the color coordinates (x,y) of the reflection calculated from the simulated spectrum and the measured spectrum are plotted on the CIE 1931 chromaticity diagram, showing a very good match with each other.

[0119] Next, FIG. 9A depicts a calculated angle-resolved reflectance spectrum with a flat scattering feature under non-polarized light illumination, showing a close match to the measured results in FIG. 9B . From both the simulation and measurement results, the reflectance peaks remain fairly constant with respect to viewing angles up to ±60°, which is a direct result of the high refractive index of the materials (i.e., a-Si, TiO2, and Si3N4) incorporated into the angle-insensitive passive filter design provided by the present disclosure. Considering that only a material deposition process is required, the proposed structure is an excellent candidate for decorative PV applications with low manufacturing cost. The photographs of the fabricated samples in FIG. 9C under ambient light illumination with a black background clearly show that a stable blue color can be seen at different viewing angles (incident angles of 0° to 60°) under ambient light illumination, further confirming the angle-invariant performance of the passive filter design of the present invention. Note that a black background is used to simulate a c-Si photovoltaic panel that absorbs transmitted light.

[0120] The colorful appearance of broadband transmission and reflection can be explained by multiple resonances at different wavelengths in the dielectric stack. In Figure 10A, a net phase shift is drawn for each dielectric layer, which includes two reflection phase shifts and propagation phase accumulation from the interface. Transmission is effectively enhanced at those wavelengths where the net phase shift is equal to a multiple of 2π, that is, Fabry-Perot (FP) resonance is produced to reduce reflection, thereby causing transmission. Specifically, the reflection drop at about 300nm is caused by the resonance inside SiO2 (resonance at 298nm) and Si3N4 (resonance at 285nm). By simultaneously exciting multiple resonances in each layer (resonance at 381nm, 579nm and 623nm in SiO2, resonance at 381nm and 577nm in top TiO2, resonance at 396nm and 572nm in bottom TiO2, resonance at 394nm and 578nm in Si3N4), the light transmission near 400nm and 600nm is significantly improved. Similarly, reflections at longer wavelengths (including about 800 nm, about 1000 nm, and about 1100 nm) are well suppressed by the corresponding resonances as shown (resonances at 839 nm, 943 nm, and 1132 nm in SiO2, resonances at 1132 nm in top TiO2, resonances at 799 nm, 974 nm, and 1133 nm in bottom TiO2, and resonances at 803 nm, 1035 nm, and 1134 nm in Si3N4). Due to multiple resonances spanning nearly the entire solar spectrum, broadband transmission is achieved with passive filters having only 5 layers prepared according to certain aspects of the present disclosure, which improves the overall PCE of the final integrated solar cell / PV system.

[0121] On the other hand, there are still unsuppressed reflections between adjacent resonances (e.g., reflection peaks at 347 nm (16%), 452 nm (40%), 662 nm (7%), and 946 nm (4%)) because these resonances cannot cover every point in the entire range. The higher reflection intensity at 452 nm (due to both the strong absorption and low refractive index of a-Si at short wavelengths less than 400 nm and longer wavelengths greater than 650 nm, respectively) compared to the reflection intensity at other wavelengths directly causes the blue reflection appearance of the structure here.

[0122] Figure 10B provides the evolution of the spectrum of the structure of adding these 4 dielectric material layers subsequently.The reduction (black line) of the wavelength in the spectrum of the reflection intensity with the single 5nm a-Si layer clearly shows that the high refractive index directly causes strong reflection, which is consistent with the explanation proposed above.After only TiO2 is placed on the top, strong reflection peak occurs immediately in the blue range, and reflection is suppressed at about 400nm and about 600nm simultaneously.By adding SiO2 and other two kinds of dielectrics on the back side of the a-Si layer, by exciting other transmission resonances, further reduce the reflection outside the scope of 400nm to 500nm, thereby realize the optimized structure.It is worth noting that the spectrum is very close to the final result of the two kinds of dielectrics (TiO2 and SiO2) on the top, which means that when realizing the final high transmission, the top dielectric plays a more important role than the bottom stack.

[0123] On the other hand, the high efficiency of broadband transmission is generated by the anti-reflection (AR) effect of the dielectric layer with gradient refractive index distribution. This can be verified by plotting the optical admittance diagram, which provides an effective way to visualize the optical surface admittance of multilayer structures. is the inverse of the impedance (where ε and μ are the dielectric constant and permeability, respectively) and is equal to the material complex refractive index due to negligible magnetic effects at optical frequencies. The admittance locus is circular for transparent dielectrics and ideal electrical conductors and spiral for absorbing materials such as semiconductors and real metals. The admittance of the structure starts from the substrate and rotates along a circular or spiral locus as the thickness increases. The distance between the end admittance point of the layered structure and the admittance of air (1,0) is determined by

[0124]

[0125] Where Y0 and Y1 refer to the air admittance and the end admittance point of the structure respectively. Fig.11Admittance plots of passive reflective blue color filter structures prepared according to certain aspects of the present disclosure at different wavelengths including 300 nm, 400 nm, 450 nm, 600 nm, 800 nm, 1000 nm, and 1100 nm are plotted. The length of the black line connecting the ending admittance point of the structure and air provides a measure of the reflectivity of the structure. The final admittance positions are (0.76, -0.07), (1.04, -0.71), (4.33, 0.40), (1.22, -0.07), (1.07, 0.07), (1.16, 0.04), and (1.04, 0.03), corresponding to reflections of approximately 2.01%, 10.84%, 39.37%, 1.08%, 0.23%, 0.58%, and 0.06%, respectively. For simplicity, the silica substrate backside reflection is ignored in the calculations here. The blue appearance and broadband high transmission are well illustrated by the only strong reflection intensity at 450 nm.

[0126] Fig.12 The measured current density-voltage (JV) characteristics of an angle-insensitive color photovoltaic device assembly (PV system) combined with a blue angle-insensitive passive reflective filter and an integrated photovoltaic device are shown compared to a c-Si panel photovoltaic without a passive filter. Due to the overall high transmission harvested through the c-Si cell through the overhead filter, the entire PV system shows about 38.44 mA cm -2 The short-circuit current density J sc , open circuit voltage V of about 585.0mV oc , a fill factor (FF) of about 75.69%, corresponding to a PCE of about 17.02%, which is only slightly higher than that of the pristine c-Si solar cell without color filter coverage (J sc About 42.21 mA cm -2 , V oc The efficiency of the colored solar cell is about 3.16% lower than that of the conventional colored PV (about 611.2 mV, FF about 78.23%, corresponding to a PCE of about 20.18%). This colored solar cell with high efficiency effectively overcomes the low efficiency limitation of conventional colored PV. As mentioned above, the overall PCE can be further enhanced if a refractive index matching layer is used between the passive filter and the underlying c-Si photovoltaic cell to reduce the about 3.5% "background" reflection from the back of the silicon dioxide substrate.

[0127] In practical applications exposed to sunlight, even brighter reflective colors are often required for use as decorative surfaces, which can be achieved by increasing the thickness of the high refractive index layer (e.g., a-Si layer) from, for example, 5 nm to 10 nm to produce a stronger reflection. Taking blue as an example, FIG. 13A shows a schematic diagram of a structure with different layer thicknesses that produces a blue reflection (FIG. 13B) with a peak intensity of 55% at 416 nm. In this filter design, the thickness of the ultra-thin reflective layer of a-Si is about 10 nm, the thickness of the first layer of SiO2 is about 145 nm, the thickness of the second layer of TiO2 is about 100 nm, the thickness of the third layer of TiO2 is about 25 nm, and the thickness of the fourth layer of Si3N4 is about 110 nm.

[0128] FIG13C shows a photograph of a fabricated sample with a black substrate showing bright blue reflection, demonstrating the remarkable angle-insensitive performance of the new design with higher reflection intensity. Due to the unaffected high transmission over the entire broadband wavelength range, the integration of higher brightness filters into c-Si cells (with about 35.23 mA cm -2 J sc , V about 582.90mV oc After being placed on top of the passive filter with enhanced reflection, the new PV system maintains a PCE of about 15.49% (FIG. 13D). In addition, by simply adjusting the thickness of the four dielectric layers (Si3N4 / TiO2 / TiO2 / SiO2), different types of blue with resonant reflections of 56% at 455nm and 55% at 477nm, respectively, are experimentally demonstrated, providing more options for practical use. Table 2 lists the detailed structures of these three blue colors produced by the passive filter with enhanced reflection.

[0129] Table 2

[0130]

[0131] In multiple aspects, the present disclosure provides an angle-insensitive color photovoltaic device assembly that combines an angle-insensitive passive color reflective filter and an integrated photovoltaic device. By integrating the passive color filter on top of the c-Si solar panel / photovoltaic device, the PCE of such a color cascade solar cell system can be greater than 18%. The passive color reflective filter includes only five layers, in which a lossy semiconductor with a high refractive index is sandwiched between two stacks or pairs of dielectrics. The passive color reflective filter utilizes a gradient refractive index distribution. The unique reflection color and the overall high transmission across the entire solar spectrum (where the latter is subsequently harvested by the c-Si photovoltaic panel below the filter) together produce a high PCE. Due to the high refractive index semiconductor materials involved in the filter module, the entire system provides high brightness and a significant angle-invariant appearance, for example, up to ±60°. In addition, by adjusting the thickness of the dielectric layer and the semiconductor layer, different reflection colors with controllable intensity can be easily achieved. Considering that only direct deposition methods are involved in the manufacture of the structure with high PCE characteristics provided by the present disclosure, the present teaching overcomes many limitations associated with typical color solar cells.

[0132] A green active angle-insensitive solar cell was fabricated according to the design described in FIG. 14A for demonstration and shown in FIG. 14B (patterned area for electrical measurements). The solar cell maintains broadband high transmission except at the wavelength used for color generation (as shown in FIG. 14C), and an additional 2.80% PCE is obtained with only 11 nm a-Si ( FIG. 14D ), which can further enhance the efficiency of the entire tandem solar panel (where the active angle-insensitive filter is coupled to a second photovoltaic cell / device). Fig.15 As shown in the simulation results in , other colors (blue and red) can also be achieved by slightly adjusting the thickness of each layer. Table 1 summarizes the detailed design of all red-green-blue (RGB) color a-Si solar cells prepared according to the present disclosure.

[0133] Table 3

[0134] AZO p-SiOx a-Si n-SiOx ITO blue 1μm 19nm 10nm 19nm 105nm green 1μm 19nm 13nm 19nm 135nm red 1μm 19nm 55nm 19nm 170nm

[0135] Table 3 shows the thickness of each layer of the reflective RGB color active filter a-Si solar cell prepared according to certain aspects of the present disclosure. The deposition conditions of all materials involved in forming these color a-Si solar cells are as follows. First, n-SiO was prepared by RF (f=13.56 MHz) plasma enhanced chemical vapor deposition technology at a temperature of 210°C. x The flow rates of SiH4, H2 and CO2 are 2sccm, 300sccm and 3sccm respectively. PH3 is used as SiO xThe n-type dopant of the layer was 2 sccm. The deposition pressure and power density were 1.3 Torr and 69 mW / cm. The deposition rate was 0.8 nm / min. The distance between the substrate and the electrode was about 20 mm.

[0136] p-SiO was fabricated by RF plasma enhanced chemical vapor deposition at 200 °C. x The flow rates of SiH4, H2 and CO2 were 400sccm, 2sccm and 0.5sccm respectively. B2H6 was used as x The deposition pressure and power density were 1.3 Torr and 69 mW / cm 2 The distance between the substrate and the electrode is about 20 mm.

[0137] The ITO thin film was grown by reactive thermal evaporation at a substrate temperature of 175° C. In / Sn alloy (10 wt % Sn) and oxygen were used as raw materials. The oxygen partial pressure was 0.25 Pa. The thickness was 75 nm and the deposition rate was 0.625 nm / sec.

[0138] a-Si was prepared by RF plasma enhanced chemical vapor deposition at 160°C. The flow rates of SiH4 and H2 were 250 sccm and 20 sccm, respectively. The deposition pressure and power density were 1.9 Torr and 49 mW / cm 2 .

[0139] The AZO electrode was formed under the following sputtering conditions: temperature: 325° C.; pressure: 1.5 mTorr; power: 150 W; time: 8 hours.

[0140] For the purpose of illustration and description, the foregoing description of the embodiments is provided. It is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and can be used in selected embodiments where applicable, even if not specifically shown or described. Also, it can be varied in many ways. Such variations are not considered to depart from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A color filter for use with a photovoltaic device, the filter comprising: an ultra-thin reflective layer comprising silicon, having a thickness less than or equal to 15 nm, and defining a first side and a second side; a transparent first pair of dielectric materials adjacent to the first side of the ultra-thin reflective layer, wherein the first pair comprises a first layer of a dielectric material and a second layer of a different dielectric material; and a transparent second pair of dielectric materials adjacent to said second side of said ultra-thin reflective layer, wherein said second pair comprises a third layer of a dielectric material and a fourth layer of a different dielectric material, wherein said filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range greater than 300 nm and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output in the visible range that exhibits minimal angular dependence.

2. The color filter of claim 1 , wherein the reflected output exhibits minimal angular dependence such that the second predetermined wavelength range varies by less than or equal to 80 nm at an incident angle of 0° to 60° relative to the color filter to form an angle-insensitive color filter. 3 . The color filter according to claim 1 , wherein the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material. 4 . The color filter according to claim 1 , wherein a thickness of the ultra-thin reflective layer is greater than or equal to 5 nm and less than or equal to 12 nm.

5. The color filter of claim 1, wherein the reflected output has a color selected from the group consisting of red, green, blue, and combinations thereof.

6. The color filter according to claim 1, wherein the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), titanium oxide (TiO2) and silicon dioxide (SiO2), zinc oxide (ZnO), hafnium oxide (HfO2), molybdenum trioxide (MoO3), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), tungsten trioxide (WO3), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and a polymer having a refractive index greater than or equal to 1.

6.

7. The color filter according to claim 1, wherein the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), zinc selenide (ZnSe), titanium oxide (TiO2) and silicon dioxide (SiO2).

8. The color filter according to claim 1, wherein: The first layer comprises silicon dioxide (SiO2), the second layer comprises titanium oxide (TiO2), the third layer comprises titanium oxide (TiO2), and the fourth layer comprises silicon nitride (Si3N4); or The first layer includes silicon nitride (Si3N4), the second layer includes zinc selenide (ZnSe), the third layer includes zinc selenide (ZnSe), and the fourth layer includes silicon nitride (Si3N4).

9. The color filter according to claim 1, wherein the thickness of the first layer is greater than or equal to 50 nm and less than or equal to 300 nm, the thickness of the second layer is greater than or equal to 10 nm and less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm and less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 50 nm and less than or equal to 300 nm.

10. The color filter according to claim 1, wherein the reflection output having the second predetermined wavelength range exhibits a blue color, wherein the thickness of the ultra-thin reflection layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 50 nm to less than or equal to 200 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 150 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 150 nm, and the thickness of the fourth layer is greater than or equal to 50 nm to less than or equal to 200 nm.

11. The color filter according to claim 1, wherein the reflection output having the second predetermined wavelength range exhibits a green color, wherein the thickness of the ultra-thin reflection layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 100 nm to less than or equal to 200 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 100 nm to less than or equal to 200 nm.

12. The color filter according to claim 1, wherein the reflection output having the second predetermined wavelength range exhibits a red color, wherein the thickness of the ultra-thin reflection layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 100 nm to less than or equal to 300 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 100 nm to less than or equal to 300 nm.

13. An angle-insensitive color photovoltaic device assembly, comprising: A color reflective filter, the color reflective filter comprising: an ultra-thin reflective layer comprising silicon, having a thickness less than or equal to 15 nm, and defining a first side and a second side; a transparent first pair of dielectric materials adjacent to said first side of said ultra-thin reflective layer, wherein said first pair comprises a first layer of a dielectric material and a second layer of a different dielectric material; a transparent second pair of dielectric materials adjacent to said second side of said ultra-thin reflective layer, wherein said second pair comprises a third layer of a dielectric material and a fourth layer of a different dielectric material, wherein said filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range greater than 300 nm and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output in the visible range that exhibits minimal angular dependence; and A photovoltaic device is adjacent to the color reflective filter, wherein the photovoltaic device comprises at least one photosensitive material that receives the first portion of the electromagnetic spectrum having a first predetermined wavelength range greater than 300 nm.

14. The angle-insensitive color photovoltaic device assembly according to claim 13, wherein the power conversion efficiency of the photovoltaic device is greater than or equal to 18%.

15. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the photosensitive material comprises crystalline silicon (c-Si) material.

16. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material.

17. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the reflected output having a second predetermined wavelength range is in the visible range and has a color selected from red, green, blue, and combinations thereof.

18. An angle-insensitive color photovoltaic device assembly according to claim 13, wherein the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), titanium oxide (TiO2) and silicon dioxide (SiO2), zinc oxide (ZnO), hafnium oxide (HfO2), molybdenum trioxide (MoO3), tantalum pentoxide (Ta2O5), niobium pentoxide (Nb2O5), tungsten trioxide (WO3), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and a polymer having a refractive index greater than or equal to 1.

6.

19. The angle-insensitive color photovoltaic device assembly according to claim 13, wherein the dielectric material forming each of the first layer, the second layer, the third layer and the fourth layer is independently selected from silicon nitride (Si3N4), zinc selenide (ZnSe), titanium oxide (TiO2) and silicon dioxide (SiO2).

20. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the first layer comprises silicon dioxide (SiO2), the second layer comprises titanium oxide (TiO2), the third layer comprises titanium oxide (TiO2), and the fourth layer comprises silicon nitride (Si3N4); or The first layer includes silicon nitride (Si3N4), the second layer includes zinc selenide (ZnSe), the third layer includes zinc selenide (ZnSe), and the fourth layer includes silicon nitride (Si3N4).

21. The angle-insensitive color photovoltaic device assembly according to claim 13, wherein the thickness of the first layer is greater than or equal to 50 nm to less than or equal to 300 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 50 nm to less than or equal to 300 nm.

22. An angle-insensitive color photovoltaic device assembly according to claim 13, wherein the reflective output having a second predetermined wavelength range exhibits a blue color, wherein the thickness of the ultra-thin reflective layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 50 nm to less than or equal to 200 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 150 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 150 nm, and the thickness of the fourth layer is greater than or equal to 50 nm to less than or equal to 200 nm.

23. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the reflective output having a second predetermined wavelength range exhibits a green color, wherein the thickness of the ultra-thin reflective layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 100 nm to less than or equal to 200 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 100 nm to less than or equal to 200 nm.

24. The angle-insensitive color photovoltaic device assembly of claim 13, wherein the reflective output having a second predetermined wavelength range exhibits a red color, wherein the thickness of the ultra-thin reflective layer is greater than or equal to 5 nm to less than or equal to 12 nm, the thickness of the first layer is greater than or equal to 100 nm to less than or equal to 300 nm, the thickness of the second layer is greater than or equal to 10 nm to less than or equal to 200 nm, the thickness of the third layer is greater than or equal to 10 nm to less than or equal to 200 nm, and the thickness of the fourth layer is greater than or equal to 100 nm to less than or equal to 300 nm.

25. An active color reflective filter for use with a photovoltaic device, comprising: an ultra-thin reflective layer comprising silicon, having a thickness less than or equal to 15 nm, and defining a first side and a second side; a first transparent electrode having a first polarity disposed along the first side of the ultra-thin reflective layer; and A second transparent electrode having a second polarity opposite to the first polarity is arranged along the second side of the ultra-thin reflective layer, wherein the active color reflective filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range greater than 300nm and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output in the visible light range that shows minimal angular dependence.

26. An active color reflective filter according to claim 25, wherein the reflective output exhibits minimal angular dependence such that the second predetermined wavelength range varies by less than or equal to 80 nm at an incident angle of 0° to 60° relative to the active color reflective filter to form an angle-insensitive active reflective color filter.

27. The active color reflective filter according to claim 25, further comprising a first charge transport layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second charge transport layer disposed between the ultra-thin reflective layer and the second transparent electrode.

28. The active color reflective filter according to claim 25, further comprising a first doping layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second doping layer disposed between the ultra-thin reflective layer and the second transparent electrode.

29. The active color reflective filter according to claim 28, wherein the ultra-thin reflective layer comprises an amorphous silicon (a-Si) material, and the first doped layer comprises an n-doped silicon oxide (SiO x ), the second doped layer comprises p-doped silicon oxide (SiO x ), and the first transparent electrode and the second transparent electrode independently include a material selected from the following: aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), indium zinc oxide (IZO), magnesium and gallium co-doped zinc oxide (MGZO), boron-doped zinc oxide (BZO), and combinations thereof.

30. The active color reflective filter according to claim 28, wherein the thickness of the first transparent electrode is greater than or equal to 50 nm and less than or equal to 200 nm, the thickness of the second transparent electrode is greater than or equal to 750 nm and less than or equal to 1.5 micrometers, the thickness of the first doping layer is greater than or equal to 10 nm and less than or equal to 20 nm, the thickness of the second doping layer is greater than or equal to 5 nm and less than or equal to 20 nm, and the thickness of the ultra-thin reflective layer is greater than or equal to 5 nm and less than or equal to 55 nm.

31. An angle-insensitive color photovoltaic device assembly, comprising: An active color reflective filter, the active color reflective filter comprising: an ultra-thin reflective layer comprising silicon, having a thickness less than or equal to 15 nm, and defining a first side and a second side; a first transparent electrode having a first polarity disposed along the first side of the ultra-thin reflective layer; a second transparent electrode having a second polarity opposite to the first polarity disposed along the second side of the ultra-thin reflective layer, wherein the active color reflective filter is capable of transmitting a first portion of the electromagnetic spectrum having a first predetermined wavelength range greater than 300 nm and reflecting a second portion of the electromagnetic spectrum having a second predetermined wavelength range to produce a reflective output in the visible range that exhibits minimal angular dependence; and A photovoltaic device is adjacent to the active color reflective filter, wherein the photovoltaic device comprises at least one photosensitive material receiving the first portion of the electromagnetic spectrum having the first predetermined wavelength range greater than 300 nm.

32. An angle-insensitive color photovoltaic device assembly according to claim 31, wherein the first transparent electrode and the second transparent electrode comprise materials independently selected from indium tin oxide (ITO) and indium zinc oxide (IZO), the ultra-thin reflective layer comprises amorphous silicon (a-Si) material, and the photosensitive material comprises crystalline silicon (c-Si).

33. The angle-insensitive color photovoltaic device assembly of claim 31, wherein the active color reflective filter further comprises a first doped layer disposed between the first transparent electrode and the ultra-thin reflective layer and a second doped layer disposed between the ultra-thin reflective layer and the second transparent electrode.

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