Optical-electric conversion device and preparation method and application thereof

Abstract

The invention discloses a light-electricity conversion device and a preparation method and application thereof. The light-electricity conversion device comprises a first electrode, a hole transport layer, a semiconductor function layer, an electron transport layer and a second electrode which are sequentially stacked. The conduction band energy level of the electron transport layer is matched with the conduction band energy level of the semiconductor function layer; the valence band energy level of the electron transport layer is deeper than that of the semiconductor function layer; the valence band energy level of the hole transport layer is matched with the valence band energy level of the semiconductor function layer; the conduction band energy level of the hole transport layer is shallower than the conduction band energy level of the semiconductor function layer. According to the photoelectric conversion device, through the arrangement of the hole transport layer and the electron transport layer, energy level arrangement in the device structure is optimized, extraction and injection of charges are balanced, dissociation and recombination of excitons in the semiconductor function layer are promoted, and the dual functions of photoelectric conversion and electro-photoelectric conversion are achieved in a single device.

Description

Technical Field

[0001] The present invention belongs to the field of optoelectronic technology, and in particular relates to an optical-electrical conversion device and a preparation method and application thereof. Background Art

[0002] Metal halide perovskites have the characteristics of long carrier diffusion length, high fluorescence quantum yield, bipolar transmission, good absorption and luminescence, and are widely used in the fields of solar cells and light-emitting diodes. Both perovskite solar cells and perovskite light-emitting diodes can be constructed through conventional pin and nip structures. The difference is that in order to achieve efficient carrier extraction or carrier injection, the corresponding energy level structure needs to be designed. Therefore, as long as the structure is designed reasonably, in theory, the dual functions of photovoltaic and light-emitting can be achieved in the same device. However, the energy band structure design strategy of traditional battery devices and light-emitting devices is difficult to take into account the two opposite requirements of efficient charge extraction and injection. At present, only near-infrared perovskites with narrow band gaps have achieved relatively considerable reversible conversion efficiency, while the development of wide-bandgap visible light perovskite dual-functional devices with a wider range of applications is still greatly restricted. Summary of the invention

[0003] In order to overcome at least one of the problems existing in the above-mentioned prior art, one of the objects of the present invention is to provide a photoelectric conversion device which has both photovoltaic and luminescent properties and can realize the dual functions of photoelectric conversion and electro-photoelectric conversion in a single device.

[0004] A second object of the present invention is to provide a method for preparing the above-mentioned photoelectric conversion device.

[0005] A third object of the present invention is to provide a photoelectric conversion device including the above-mentioned photoelectric conversion device.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A first aspect of the present invention provides a photoelectric conversion device, comprising a first electrode, a hole transport layer, a semiconductor functional layer, an electron transport layer, and a second electrode stacked in sequence;

[0008] The conduction band energy level of the electron transport layer matches the conduction band energy level of the semiconductor functional layer; the valence band energy level of the electron transport layer is deeper than the valence band energy level of the semiconductor functional layer;

[0009] The valence band energy level of the hole transport layer matches the valence band energy level of the semiconductor functional layer; and the conduction band energy level of the hole transport layer is shallower than the conduction band energy level of the semiconductor functional layer.

[0010] In some specific embodiments of the present invention, the semiconductor functional layer comprises a direct bandgap semiconductor material; the direct bandgap semiconductor material comprises at least one of metal halide perovskite, gallium nitride, cadmium selenide or indium phosphide.

[0011] In some specific embodiments of the present invention, the chemical formula of the metal halide perovskite is AMX 3 or L 2 A n- 1 M n X 3n+1 ;

[0012] wherein, A represents a monovalent cation, and A comprises at least one of Cs + , Rb + , MA + , FA + or GA + ;

[0013] M represents a divalent cation, and M comprises at least one of Pb 2+ , Sn 2+ , Mn 2+ , Ca 2+ or Zn 2+ ;

[0014] X represents a monovalent anion, and X comprises at least one of F - , Cl - , Br - , I - , (BF 4 ) - or SCN - ;

[0015] L represents a monovalent cation, and L comprises at least one of EA + , PA + , i-PA + , BA + , i-BA + , t-BA + , HA + , OA + , PhA + , PMA + , PEA + , PPA + or NMA + ;

[0016] n is from 1 to 10.

[0017] In some specific embodiments of the present invention, the electron transport layer includes at least one of the following layer structures: a first electron single-layer structure composed of a first electron transport layer; a second electron multi-layer structure composed of a first electron transport layer and a second electron transport layer stacked; a third electron multi-layer structure composed of a first electron transport layer, a second electron transport layer, and a third electron transport layer stacked in sequence; a fourth electron multi-layer structure composed of a first electron transport layer, a mixed electron transport layer, a second electron transport layer, and a third electron transport layer stacked in sequence;

[0018] wherein the first electron transport layer, the second electron transport layer, and the third electron transport layer each independently include at least one electron transport material; the mixed electron transport layer includes at least two electron transport materials.

[0019] In some specific embodiments of the present invention, the electron transport layer includes an electron transport material; the electron transport material includes at least one of 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine, 4,6-bis(3,5-bis(3-pyridyl)phenyl)-2-methylpyrimidine, 4,6-bis(3,5-bis(4-pyridyl)phenyl)-2-methylpyrimidine, tris[2,4,6-trimethyl-3-(3-pyridyl)phenyl]borane, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, fullerene C 60 fullerene C 70 [6,6]-phenyl C 61 methyl butyrate, [6,6]-phenyl C71 methyl butyrate, 2,7-bis(3-(dimethylamino)propyl)benzo[lmno][3,8]phenanthroline-1,3,6,8(2H,7H)-tetrone, zinc oxide, or tin dioxide.

[0020] In some specific embodiments of the present invention, the hole transport layer includes at least one of the following layer structures: a first hole single-layer structure composed of a first hole transport layer; a second hole multi-layer structure composed of a first hole transport layer and a second hole transport layer stacked;

[0021] wherein the first hole transport layer and the second hole transport layer each independently include at least one hole transport material.

[0022] In some specific embodiments of the present invention, the hole transport layer comprises a hole transport material; the hole transport material comprises at least one of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), nickel oxide, molybdenum trioxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(9-vinylcarbazole), poly[(9,9-dioctylfluorene-2,7-diyl)-alt-(4,4'-(N-(4-butyl)phenyl)-diphenylamine)], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(9H-carbazol-9-yl)butyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid or [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid.

[0023] In some specific embodiments of the present invention, the thickness of the first electrode is 1 to 200 nm.

[0024] In some specific embodiments of the present invention, the thickness of the hole transport layer is 0.5 to 30 nm.

[0025] In some specific embodiments of the present invention, the thickness of the semiconductor functional layer is 50 to 2000 nm.

[0026] In some specific embodiments of the present invention, the thickness of the electron transport layer is 0.5 to 100 nm.

[0027] In some specific embodiments of the present invention, the thickness of the second electrode is 1 to 200 nm.

[0028] The second aspect of the present invention provides a method for preparing an optoelectronic conversion device as described in the first aspect of the present invention, comprising the following steps: sequentially preparing the first electrode, the hole transport layer, the semiconductor functional layer, the electron transport layer and the second electrode to obtain the optoelectronic conversion device.

[0029] The third aspect of the present invention provides an optoelectronic conversion device, comprising the optoelectronic conversion device as described in the first aspect of the present invention.

[0030] The beneficial effects of the present invention are as follows: through the arrangement of the hole transport layer and the electron transport layer, the energy level arrangement in the device structure is optimized, the extraction and injection of charges are balanced, the dissociation and recombination of excitons in the semiconductor functional layer are promoted, and the dual functions of optoelectronic conversion and electro-optical conversion are realized in a single device. Description of the Drawings

[0031] Figure 1 Schematic diagram of the energy level structure in some embodiments of the present invention.

[0032] Figure 2 Schematic diagram of the structure of the optoelectronic conversion device in Embodiment 1 of the present invention.

[0033] Figure 3 For FAPbBr in Embodiment 1 of the present invention 3 UV-Vis absorption spectrum of the perovskite layer.

[0034] Figure 4 For FAPbBr in Embodiment 1 of the present invention 3 Steady-state fluorescence spectrum of the perovskite layer.

[0035] Figure 5 For FAPbBr in Embodiment 1 of the present invention 3 Scanning electron microscope image of the perovskite layer.

[0036] Figure 6 Photovoltaic performance test results of the devices in Embodiments 1-2 and Comparative Example 1 of the present invention.

[0037] Figure 7 Brightness-voltage curves of the devices in Embodiments 1-2 and Comparative Example 1 of the present invention.

[0038] Figure 8 External quantum efficiency-brightness curves of the devices in Embodiments 1-2 of the present invention.

[0039] Figure 9 Electroluminescence spectra of the device in Embodiment 2 of the present invention under different bias voltages. Detailed implementation manners

[0040] The content of the present invention will be further described in detail through specific embodiments below. It should be understood that the following embodiments are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles described in the present invention fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range according to the description herein, rather than being limited to the specific data in the following examples. The raw materials, reagents or devices used in the following examples and comparative examples can be obtained from conventional commercial channels or can be obtained by existing known methods without special instructions.

[0041] Hereinafter, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. As used in this specification and the appended claims, the singular forms "a" and "the" also include plural referents unless the context clearly dictates otherwise. In the description of the embodiments of the present invention, unless otherwise stated, the meaning of "at least one" is one or more than one, and the meaning of "at least two" is two or more than two.

[0042] In a first aspect of an embodiment of the present invention, there is provided an optoelectronic conversion device, including a first electrode, a hole transport layer, a semiconductor functional layer, an electron transport layer, and a second electrode that are sequentially stacked.

[0043] The conduction band energy level of the electron transport layer matches the conduction band energy level of the semiconductor functional layer; the valence band energy level of the electron transport layer is deeper than the valence band energy level of the semiconductor functional layer.

[0044] The valence band energy level of the hole transport layer matches the valence band energy level of the semiconductor functional layer; the conduction band energy level of the hole transport layer is shallower than the conduction band energy level of the semiconductor functional layer.

[0045] The valence band energy level refers to the highest energy level of the full band occupied by valence electrons; the conduction band energy level refers to the lowest energy level reached by some electrons in the valence band crossing the forbidden band and entering the empty band with higher energy; the energy gap is between the conduction band energy level and the valence band energy level.

[0046] The schematic diagram of the energy level structure in some embodiments of the present invention is as Figure 1 shown. In the above embodiments, by setting the electron transport layer, the conduction band energy level of the electron transport layer is made to match the conduction band energy level of the semiconductor functional layer, which is beneficial for the electron transport layer to inject electrons into the semiconductor functional layer and extract electrons. At the same time, the electron transport layer has a deeper valence band energy level than the semiconductor functional layer, which can effectively block holes from the semiconductor functional layer and prevent hole leakage. Further, by setting the hole transport layer, the valence band energy level of the hole transport layer is made to match the valence band energy level of the semiconductor functional layer, which is beneficial for the hole transport layer to inject holes into the semiconductor functional layer and extract holes. At the same time, the hole transport layer has a shallower conduction band energy level than the semiconductor functional layer, which can effectively block electrons from the semiconductor functional layer and prevent electron leakage.

[0047] In the above embodiments, energy level matching means that the energy level difference between two energy levels is less than or equal to 0.5 eV.

[0048] For example, the matching of the conduction band energy level of the electron transport layer with that of the semiconductor functional layer means that the energy level difference between the conduction band energy level of the electron transport layer and that of the semiconductor functional layer is less than or equal to 0.5 eV; it can be any one of 0 eV, 0.1 eV, 0.2 eV, 0.3 eV, 0.4 eV, or 0.5 eV or a range value between any two of them; it can be that the conduction band energy level of the electron transport layer is slightly higher than, slightly lower than, or equal to that of the semiconductor functional layer.

[0049] For another example, the matching of the valence band energy level of the hole transport layer with that of the semiconductor functional layer means that the energy level difference between the valence band energy level of the hole transport layer and that of the semiconductor functional layer is less than or equal to 0.5 eV; it can be any one of 0 eV, 0.1 eV, 0.2 eV, 0.3 eV, 0.4 eV, or 0.5 eV or a range value between any two of them; it can be that the valence band energy level of the hole transport layer is slightly higher than, slightly lower than, or equal to that of the semiconductor functional layer.

[0050] Reference Figure 1 , the valence band energy levels of the electron transport layer and the semiconductor functional layer are both negative values. Therefore, when the difference between the valence band energy levels of the electron transport layer and the semiconductor functional layer is greater than the hole blocking threshold, that is, when the valence band energy level of the electron transport layer is deep enough relative to that of the semiconductor functional layer, hole leakage can be blocked. The hole blocking threshold here refers to the energy level value that can enable the electron transport layer to have the required hole blocking function, and can be specifically set according to actual requirements.

[0051] Continue to refer to Figure 1 , the conduction band energy levels of the hole transport layer and the semiconductor functional layer are both negative values. Therefore, when the difference between the conduction band energy levels of the hole transport layer and the semiconductor functional layer is greater than the electron blocking threshold, that is, when the conduction band energy level of the hole transport layer is shallow enough relative to that of the semiconductor functional layer, electron leakage can be blocked. The electron blocking threshold here refers to the energy level value that can enable the hole transport layer to have the required electron blocking function, and can be specifically set according to actual requirements.

[0052] The optoelectronic conversion device of the present invention optimizes the energy level arrangement in the device structure, balances the extraction and injection of charges, and promotes the dissociation and recombination of excitons in the semiconductor functional layer through the settings of the hole transport layer and the electron transport layer, realizing the dual functions of optoelectronic conversion and electro-optical conversion in a single device. When the device is irradiated by an external light source, the semiconductor functional layer can absorb photon energy to form excitons; the free electrons and holes formed by the dissociation of excitons can be extracted by the electron transport layer and the hole transport layer respectively and migrate to the cathode and anode to form a current in the circuit. When the device is excited by an external voltage, electrons and holes can be injected into the perovskite layer from the electron transport layer and the hole transport layer respectively and emit light through radiative recombination. The resulting optoelectronic conversion device can spontaneously realize the recycling of energy.

[0053] In some embodiments of the present invention, the semiconductor functional layer comprises a direct bandgap semiconductor material.

[0054] In some embodiments of the present invention, the direct bandgap semiconductor material comprises at least one of metal halide perovskite, gallium nitride, cadmium selenide or indium phosphide; in some specific embodiments of the present invention, the direct bandgap semiconductor material is selected from metal halide perovskite.

[0055] In some embodiments of the present invention, the structure of the metal halide perovskite includes a three-dimensional perovskite structure (AMX 3 ), a two-dimensional perovskite structure (L 2 A n-1 M n X 3n+1 ), a quasi-two-dimensional perovskite structure (L 2 A n-1 M n X 3n+1 ) or a perovskite nanocrystal structure.

[0056] In the above embodiments, for the three-dimensional perovskite structure, the inorganic layer materials are interconnected through [MX 6 4- octahedrons, and A ions are embedded in the voids between adjacent octahedrons. For the two-dimensional or quasi-two-dimensional perovskite structure, the inorganic layer materials are embedded and separated by L ions to form quantum wells with different n values, where n represents the number of layers of [MX 6 4- . For the perovskite nanocrystal structure, the perovskite is encapsulated by large-sized organic cations or metal ion ligands to form perovskite crystals with nanoscale dimensions.

[0057] ​​In some embodiments of the present invention, metal halide perovskite is used to prepare a semiconductor functional layer, which has good light absorption and light emission characteristics. Metal halide perovskite can absorb photon energy to generate excitons, and the excitons dissociate to form free electrons and holes, realizing the photovoltaic function. At the same time, the free electrons and holes can attract each other under the excitation of an external voltage to form excitons, and the excitons generate photons through radiative recombination, realizing the light emission function. Therefore, the device can achieve the photovoltaic-light emission dual function in different scenarios.

[0058] In some embodiments of the present invention, the chemical formula of the metal halide perovskite is AMX 3 or L 2 A n-1 M n X 3n+1 ;

[0059] Among them, A represents a monovalent cation, and A includes Cs + (cesium ion), Rb + (rubidium ion), MA + (methylammonium ion), FA + (formamidinium ion) or GA + (guanidinium ion) and at least one of them;

[0060] M represents a divalent cation, and M includes Pb 2+ (lead ion), Sn 2+ (tin ion), Mn 2+ (manganese ion), Ca 2+ (calcium ion) or Zn 2+ (zinc ion) and at least one of them;

[0061] X represents a monovalent anion, and X includes F - (fluoride ion), Cl - (chloride ion), Br - (bromide ion), I - (iodide ion), (BF 4 ) - (tetrafluoroborate ion) or SCN - (thiocyanate ion) and at least one of them;

[0062] L represents a monovalent cation, and L includes EA + (ethylammonium ion), PA + (propylammonium ion), i-PA + (isopropylammonium ion), BA + (butylammonium ion), i-BA + (isobutylammonium ion), t-BA + (tert-butylammonium ion), HA + (hexylammonium ion), OA + (octylammonium ion), PhA+ (aniline ion), PMA + (benzylamine ion), PEA + (phenethylamine ion), PPA + (amphetamine ion) or NMA + at least one of (naphthylmethylamine ion);

[0063] n is from 1 to 10.

[0064] In the above embodiments, the chemical formula of the metal halide perovskite and the types of ions are only examples, and those skilled in the art can select according to actual needs to achieve the specific energy level structure of the present invention.

[0065] In some specific embodiments of the present invention, the direct bandgap semiconductor material is selected from direct bandgap semiconductor materials with a wide bandgap; in some examples of the present invention, the bandgap of the above-mentioned direct bandgap semiconductor material with a wide bandgap is 1.65 - 3.10 eV; for example, it can be any one of 1.65 eV, 1.8 eV, 2.0 eV, 2.2 eV, 2.5 eV, 2.8 eV, 3.0 eV or 3.1 eV or the range value between any two of them; in some specific examples of the present invention, the direct bandgap semiconductor material is selected from FAPbBr 3 .

[0066] Using a direct bandgap semiconductor material with a wide bandgap to prepare a semiconductor functional layer, in the obtained device, the electroluminescence spectrum can be in the visible light range. For example, the bandgap of FAPbBr 3 is 2.28 eV, emitting green light.

[0067] In some embodiments of the present invention, the thickness of the semiconductor functional layer is 50 - 2000 nm; for example, it can be any one of 50 nm, 80 nm, 100 nm, 300 nm, 500 nm, 800 nm, 1000 nm, 1500 nm or 2000 nm or the range value between any two of them.

[0068] In some embodiments of the present invention, the first electrode and the second electrode each independently include a transparent electrode, a metal electrode or a combination thereof; in some specific embodiments of the present invention, the first electrode and the second electrode each independently include at least one of an ITO electrode, an FTO electrode, a gold electrode, a silver electrode, a copper electrode, an aluminum electrode or a platinum electrode.

[0069] The selection of the first electrode and the second electrode can be specifically adjusted according to actual needs. For example, when the first electrode is a transparent electrode and the second electrode is a metal electrode, a p-i-n structure can be fabricated; when the first electrode is a metal electrode and the second electrode is a transparent electrode, an n-i-p structure can be fabricated; or a combined structure of a transparent electrode and a metal electrode can be used, and the combination form can be at least one of doping, mixing, or laminating. Those skilled in the art can specifically set the first electrode and the second electrode according to actual needs, and the present invention does not make specific limitations.

[0070] In some examples of the present invention, the first electrode is selected from ITO electrodes; the second electrode is selected from Ag electrodes.

[0071] In some embodiments of the present invention, the thickness of the first electrode is 1 to 200 nm; for example, it can be any one of 1 nm, 5 nm, 10 nm, 50 nm, 80 nm, 100 nm, 150 nm, or 200 nm, or a range value between any two of them.

[0072] In some embodiments of the present invention, the thickness of the second electrode is 1 to 200 nm; for example, it can be any one of 1 nm, 5 nm, 10 nm, 50 nm, 80 nm, 100 nm, 150 nm, or 200 nm, or a range value between any two of them.

[0073] In some embodiments of the present invention, the electron transport layer includes at least one electron transport material; further, when the electron transport layer includes at least two electron transport materials, the combination form of the electron transport materials includes at least one of doping, mixing, or laminating.

[0074] In some embodiments of the present invention, the electron transport layer includes at least one of the following layer structures: a first electron single-layer structure composed of a first electron transport layer; a second electron multi-layer structure composed of a first electron transport layer and a second electron transport layer stacked; a third electron multi-layer structure composed of a first electron transport layer, a second electron transport layer, and a third electron transport layer stacked in sequence; a fourth electron multi-layer structure composed of a first electron transport layer, a mixed electron transport layer, a second electron transport layer, and a third electron transport layer stacked in sequence;

[0075] Among them, the first electron transport layer, the second electron transport layer, and the third electron transport layer each independently include at least one electron transport material; the mixed electron transport layer includes at least two electron transport materials.

[0076] In the above embodiments, when the first electron transport layer, the second electron transport layer, and the third electron transport layer each independently include at least two electron transport materials, the combination form of the electron transport materials includes doping or mixing; in the mixed electron transport layer, the combination form of the electron transport materials includes doping or mixing.

[0077] In some embodiments of the present invention, the electron transport layer includes an electron transport material; the electron transport material includes 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene (TPBi), 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine (PO-T2T), 4,6-bis(3,5-bis(3-pyridyl)phenyl)-2-methylpyrimidine (B3PYMPM), 4,6-bis(3,5-bis(4-pyridyl)phenyl)-2-methylpyrimidine (B4PYMPM), tris[2,4,6-trimethyl-3-(3-pyridyl)phenyl]borane (3TPYMB), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), fullerene C 60 (C 60 ), fullerene C 70 (C 70 ), [6,6]-phenyl C 61 methyl butyrate (PC 61 BM), [6,6]-phenyl C71 methyl butyrate (PC 71 BM), 2,7-bis(3-(dimethylamino)propyl)benzo[LMN][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (NDI-N), zinc oxide (ZnO) or tin dioxide (SnO 2 ) or at least one of them

[0078] In the above embodiments, the types of electron transport materials are only examples, and those skilled in the art can select according to actual needs to obtain an electron transport layer with a specific energy level structure and achieve matching with the semiconductor functional layer.

[0079] In some specific embodiments of the present invention, when the direct bandgap semiconductor material is selected from direct bandgap semiconductor materials with a wide bandgap (such as FAPbBr 3 ), the electron transport layer is selected from the following layer structures: a third electron multi-layer structure formed by sequentially laminating a first electron transport layer, a second electron transport layer, and a third electron transport layer.

[0080] In the above specific embodiments, the combination of different layer structures of the electron transport layer can better match the direct bandgap semiconductor material with a wide bandgap, thereby achieving a specific energy level arrangement.

[0081] In some examples of the present invention, in the above third electron multi-layer structure, the electron transport material in the first electron transport layer is selected from B4PYMPM, the electron transport material in the second electron transport layer is selected from C 60 , and the electron transport material in the third electron transport layer is selected from BCP.

[0082] It should be noted that in the above examples, the selection of electron transport materials in the first electron transport layer, the second electron transport layer, and the third electron transport layer is only for illustration. Those skilled in the art can achieve a good matching effect with the direct bandgap semiconductor material with a wide bandgap according to different combinations of electron transport materials.

[0083] In some other specific embodiments of the present invention, when the direct bandgap semiconductor material is selected from direct bandgap semiconductor materials with a wide bandgap (such as FAPbBr 3 ), the electron transport layer is selected from the following layer structures: a fourth electron multi-layer structure formed by sequentially laminating a first electron transport layer, a hybrid electron transport layer, a second electron transport layer, and a third electron transport layer.

[0084] In the above specific embodiments, by providing a hybrid electron transport layer between the first electron transport layer and the second electron transport layer, the overall energy level structure of the electron transport layer can be further optimized, achieving a better matching effect with the direct bandgap semiconductor material with a wide bandgap and improving the device performance.

[0085] In some examples of the present invention, in the above fourth electron multi-layer structure, the electron transport material in the first electron transport layer is selected from B4PYMPM, and the electron transport material in the hybrid electron transport layer is selected from a mixture of B4PYMPM and C 60 , the electron transport material in the second electron transport layer is selected from C 60 , and the electron transport material in the third electron transport layer is selected from BCP.

[0086] It should be noted that in the above examples, the selection of electron transport materials in the first electron transport layer, the hybrid electron transport layer, the second electron transport layer, and the third electron transport layer is only for illustration. Those skilled in the art can achieve a good matching effect with the direct bandgap semiconductor material with a wide bandgap according to different combinations of electron transport materials.

[0087] In some embodiments of the present invention, the thickness of the electron transport layer is 0.5 - 100 nm; for example, it can be any one of 0.5 nm, 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, or 100 nm or a range value between any two of them.

[0088] In some specific embodiments of the present invention, the thickness of the first electron transport layer is 0.5 - 20 nm; for example, it can be any one of 0.5 nm, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 15 nm, 18 nm, or 20 nm or a range value between any two of them.

[0089] In some specific embodiments of the present invention, the thickness of the hybrid electron transport layer is 0 to 20 nm; for example, it can be any one of 0 nm, 0.5 nm, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 15 nm, 18 nm, or 20 nm, or a range value between any two of them.

[0090] In some embodiments of the present invention, the hybrid electron transport layer includes a first electron transport material and a second electron transport material, and the mass ratio of the first electron transport material to the second electron transport material is (0.1 to 10):1; for example, it can be any one of 0.1:1, 0.3:1, 0.5:1, 1:1, 3:1, 5:1, 8:1, or 10:1, or a range value between any two of them.

[0091] In some specific embodiments of the present invention, the thickness of the second electron transport layer is 5 to 30 nm; for example, it can be any one of 5 nm, 8 nm, 10 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, or 30 nm, or a range value between any two of them.

[0092] In some specific embodiments of the present invention, the thickness of the third electron transport layer is 0.5 to 20 nm; for example, it can be any one of 0.5 nm, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 15 nm, 18 nm, or 20 nm, or a range value between any two of them.

[0093] In some embodiments of the present invention, the hole transport layer includes at least one hole transport material; further, when the hole transport layer includes at least two hole transport materials, the combination forms of the hole transport materials include at least one of doping, mixing, or laminating.

[0094] In some embodiments of the present invention, the hole transport layer includes at least one of the following layer structures: a first hole single-layer structure composed of a first hole transport layer; a second hole multi-layer structure composed of a first hole transport layer and a second hole transport layer stacked;

[0095] Wherein, the first hole transport layer and the second hole transport layer each independently include at least one hole transport material.

[0096] In the above embodiments, when the first hole transport layer and the second hole transport layer each independently include at least two hole transport materials, the combination forms of the hole transport materials include doping or mixing.

[0097] In some embodiments of the present invention, the hole transport layer includes a hole transport material; the hole transport material includes poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), nickel oxide (NiO x ) molybdenum trioxide (MoO 3) at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(9-vinylcarbazole) (PVK), poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-butyl)phenyl)-diphenylamine)] (TFB), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [4-(9H-carbazol-9-yl)butyl]phosphonic acid (4PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz) or [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz).

[0098] In the above embodiments, the types of hole transport materials are only examples, and those skilled in the art can select according to actual needs to obtain a hole transport layer with a specific energy level structure and achieve matching with the semiconductor functional layer.

[0099] In some embodiments of the present invention, in the second hole multi-layer structure, the hole transport material of the first hole transport layer includes poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), nickel oxide (NiO x ) molybdenum trioxide (MoO 3 ) at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(9-vinylcarbazole) (PVK), poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4`-(N-(4-butyl)phenyl)-diphenylamine)] (TFB), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD); the hole transport material of the second hole transport layer includes at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [4-(9H-carbazol-9-yl)butyl]phosphonic acid (4PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz).

[0100] When the hole transport layer includes a second hole multi-layer structure, the combination of the above hole transport materials is beneficial to achieving a better energy level matching effect.

[0101] In some specific embodiments of the present invention, when the semiconductor functional layer comprises a direct bandgap semiconductor material with a wide bandgap (such as FAPbBr 3 ), the hole transport layer is selected from the following layer structures: a second hole multi-layer structure formed by laminating a first hole transport layer and a second hole transport layer.

[0102] In the above specific embodiments, the combination of different layer structures of the hole transport layer can better match with the direct bandgap semiconductor material with a wide bandgap, so as to achieve a specific energy level arrangement.

[0103] In some examples of the present invention, in the above second hole multi-layer structure, the hole transport material in the first hole transport layer is selected from nickel oxide (NiO x ), and the hole transport material in the second hole transport layer is selected from [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz).

[0104] It should be noted that in the above examples, the selection of the hole transport materials in the first hole transport layer and the second hole transport layer is only an example, and those skilled in the art can achieve a good matching effect with the direct bandgap semiconductor material with a wide bandgap according to different combinations of hole transport materials.

[0105] In some embodiments of the present invention, the thickness of the hole transport layer is 0.5 - 30 nm; for example, it can be any one of 0.5 nm, 1 nm, 5 nm, 10 nm, 15 nm, 18 nm, 20 nm, 25 nm or 30 nm or the range value between any two of them.

[0106] In some specific embodiments of the present invention, the thickness of the first hole transport layer is 0.5 - 15 nm; for example, it can be any one of 0.5 nm, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm or 15 nm or the range value between any two of them.

[0107] In some specific embodiments of the present invention, the thickness of the second hole transport layer is 0.5 - 15 nm; for example, it can be any one of 0.5 nm, 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm or 15 nm or the range value between any two of them.

[0108] The second aspect of the embodiments of the present invention provides a preparation method of the opto-electronic conversion device of the first aspect of the present invention, comprising the following steps: sequentially preparing a first electrode, a hole transport layer, a semiconductor functional layer, an electron transport layer and a second electrode to obtain the opto-electronic conversion device.

[0109] The device preparation method provided in the embodiments of the present invention is simple, low-cost, miniaturizable and integrable, and has good application potential in the fields of photovoltaics, lighting, display, etc.

[0110] In some embodiments of the present invention, the methods for preparing the first electrode, the hole transport layer, the semiconductor functional layer, the electron transport layer and the second electrode independently adopt a deposition method.

[0111] In some specific embodiments of the present invention, the deposition methods adopted for preparing the first electrode, the hole transport layer, the electron transport layer and the second electrode include at least one of magnetron sputtering, atomic layer deposition, vacuum thermal evaporation, electron beam evaporation, chemical vapor deposition or solution spin coating; the deposition methods adopted for preparing the semiconductor functional layer include at least one of spin coating, blade coating, spraying, printing, inkjet printing, evaporation.

[0112] In some embodiments of the present invention, when the semiconductor functional layer includes a direct bandgap semiconductor material, and the direct bandgap semiconductor material is selected from metal halide perovskites, the chemical formula of the metal halide perovskite is AMX 3 or L 2 A n-1 M n X 3n+1 When, the specific method for preparing the semiconductor functional layer includes: depositing a mixture including a halide of A, a halide of M and an additive on the hole transport layer; or depositing a mixture including a halide of L, a halide of A, a halide of M and an additive on the hole transport layer; performing post-treatment to obtain the semiconductor functional layer.

[0113] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the halide of A includes at least one of CsCl, RbCl, MACl, FACl, GACl, CsBr, RbBr, MABr, FABr, GABr, CsI, RbI, MAI, FAI or GAI.

[0114] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the halide of M includes PbCl 2 , SnCl 2 , MnCl 2 , CaCl 2 , ZnCl 2 , PbBr 2 , SnBr 2 , MnBr 2 , CaBr 2 , ZnBr 2 , PbI 2 , SnI 2 , MnI 2 , CaI2 or ZnI 2 at least one of

[0115] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the halide of L includes at least one of ethylamine hydrochloride (EACl), propylamine hydrochloride (PACl), isopropylamine hydrochloride (i-PACl), butylamine hydrochloride (BACl), isobutylamine hydrochloride (i-BACl), tert-butylamine hydrochloride (t-BACl), hexylamine hydrochloride (HACl), octylamine hydrochloride (OACl), benzylamine hydrochloride (PMACl), phenethylamine hydrochloride (PEACl), phenylpropylamine hydrochloride (PPACl), ethylamine hydrobromide (EABr), propylamine hydrobromide (PABr), isopropylamine hydrobromide (i-PABr), butylamine hydrobromide (BABr), isobutylamine hydrobromide (i-BABr), tert-butylamine hydrobromide (t-BABr), hexylamine hydrobromide (HABr), octylamine hydrobromide (OABr), aniline hydrobromide (PhABr), benzylamine hydrobromide (PMABr), phenethylamine hydrobromide (PEABr), phenylpropylamine hydrobromide (PPABr), naphthylmethylamine hydrobromide (NMABr), ethylamine hydroiodide (EAI), propylamine hydroiodide (PAI), isopropylamine hydroiodide (i-PAI), butylamine hydroiodide (BAI), isobutylamine hydroiodide (i-BAI), tert-butylamine hydroiodide (t-BAI), hexylamine hydroiodide (HAI), octylamine hydroiodide (OAI), aniline hydroiodide (PhAI), benzylamine hydroiodide (PMAI), phenethylamine hydroiodide (PEAI), phenylpropylamine hydroiodide (PPAI) or naphthylmethylamine hydroiodide (NMAI).

[0116] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the additive includes at least one of carboxylic acid molecules, phosphoric acid molecules, sulfonic acid molecules, pyridine molecules, thiophene molecules, pyrrole molecules or silane molecules.

[0117] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the method of depositing the mixture on the hole transport layer includes at least one of spin coating, blade coating, spraying, printing, printing, evaporation coating. In some examples of the present invention, in the above specific method for preparing the semiconductor functional layer, the method of depositing the mixture on the hole transport layer specifically includes: spin coating the mixture in solution form on the hole transport layer at a spin coating speed of 500 - 6000 rpm; the above spin coating speed can be any one of 500 rpm, 1000 rpm, 2000 rpm, 4000 rpm or 6000 rpm or a range value between any two of them, such as 500 - 4000 rpm.

[0118] In some specific embodiments of the present invention, in the above specific method for preparing the semiconductor functional layer, the post-treatment includes at least one of no treatment, thermal annealing treatment, solvent treatment, or vacuum treatment.

[0119] In some examples of the present invention, the method for preparing the above-mentioned optoelectronic conversion device includes the following specific steps:

[0120] Deposit a hole transport layer on the surface of the first electrode to obtain a hole transport layer;

[0121] Deposit a mixture including a halide of A, a halide of M, and an additive on the hole transport layer; or deposit a mixture including a halide of L, a halide of A, a halide of M, and an additive on the hole transport layer; perform post-treatment to obtain a semiconductor functional layer;

[0122] Deposit an electron transport layer and a second electrode layer by layer on the semiconductor functional layer to fabricate the above-mentioned optoelectronic conversion device.

[0123] The preparation method provided in the above example has a simple process and is easy to operate. The thickness of each layer structure can be adjusted, which is beneficial to the preparation of optoelectronic conversion devices with better performance.

[0124] The third aspect of the embodiments of the present invention provides an optoelectronic conversion device, including the optoelectronic conversion device of the first aspect of the present invention.

[0125] The optoelectronic conversion device provided by the present invention can be used to prepare optoelectronic conversion devices, such as photovoltaic devices (such as solar cells), lighting devices (such as light-emitting diodes), display devices, photodetectors, etc. And this optoelectronic conversion device has both photovoltaic and light-emitting characteristics, can sensitively respond to light signals, generate electricity efficiently under light illumination, and emit light with low energy consumption in the dark, having an efficient application effect.

[0126] The following further describes the implementation of the present invention in detail with specific examples and comparative examples.

[0127] Example 1

[0128] This example provides an optoelectronic conversion device, as shown in the structural schematic diagram of Figure 2 , which includes, from bottom to top in sequence: an ITO electrode layer (180 nm); a hole transport combined layer composed of a first hole transport layer (NiO x , 15 nm) and a second hole transport layer (2PACz, about 1 nm) stacked in sequence; a three-dimensional perovskite FAPbBr 3 layer (270 nm); a first electron transport layer (B4PYMPM, 5 nm), a second electron transport layer (C 60, (20 nm), and a third electron transport layer (BCP, 5 nm) stacked in sequence to form an electron transport composite layer; a silver electrode layer (100 nm). The specific preparation process of the above device is as follows:

[0129] (1) Prepare a 0.1 mol / L nickel acetate tetrahydrate ethanol solution, and add 0.1 mol / L ethanolamine to obtain a NiO x precursor solution. Drop the NiO x precursor solution on the ITO substrate, spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 360 °C for 60 minutes to obtain the NiO x layer.

[0130] (2) Prepare a 0.5 mg / mL 2PACz ethanol solution. Drop the 2PACz ethanol solution on the NiO x layer prepared in step (2), spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 100 °C for 10 minutes to obtain the 2PACz layer.

[0131] (3) Accurately weigh 0.13747 g of formamidinium hydrobromide (FABr), 0.36701 g of lead bromide (PbBr 2 ), 0.00123 g of potassium 3-sulfopropyl methacrylate (SPM), 0.85 mL of dimethyl sulfoxide (DMSO), and 0.15 mL of N,N-dimethylformamide (DMF) into a glass bottle, and stir overnight at room temperature to fully dissolve the solutes to prepare a perovskite precursor solution.

[0132] (4) Drop the perovskite precursor solution prepared in step (3) on the 2PACz layer prepared in step (2), first spin-coat it at a speed of 500 rpm for 5 seconds, then spin-coat it at a speed of 4000 rpm for 20 seconds, and add 120 μL of a chloroform / ethyl acetate (v / v = 3:1) mixed solvent 10 seconds before the end of the second spin-coating step, and anneal it at 90 °C for 10 minutes to obtain the perovskite layer.

[0133] (5) Evaporate 5 nm of B4PYMPM, 20 nm of C 60 , 5 nm of BCP, and 100 nm of Ag electrode layer by layer on the perovskite layer prepared in step (4) through vacuum thermal evaporation to obtain the optoelectronic conversion device of this example.

[0134] Example 2

[0135] This example provides an optoelectronic conversion device, which includes, from bottom to top in sequence: an ITO electrode layer (180 nm); a hole transport composite layer composed of a first hole transport layer (NiO x , 15 nm) and a second hole transport layer (2PACz, about 1 nm) stacked in sequence; a three-dimensional perovskite FAPbBr3 Layer (270 nm); a first electron transport layer (B4PYMPM, 5 nm), a hybrid electron transport layer (B4PYMPM:C60, 5 nm), a second electron transport layer (C 60 , 20 nm), and a third electron transport layer (BCP, 5 nm) are sequentially stacked to form an electron transport composite layer; a silver electrode layer (100 nm). The specific preparation process of the above device is as follows:

[0136] (1) Prepare a 0.1 mol / L nickel acetate tetrahydrate ethanol solution, and add 0.1 mol / L ethanolamine to obtain a NiO x precursor solution. Drop the NiO x precursor solution on the ITO substrate, spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 360 °C for 60 minutes to obtain the NiO x layer.

[0137] (2) Prepare a 0.5 mg / mL 2PACz ethanol solution. Drop the 2PACz ethanol solution on the NiO x layer prepared in step (2), spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 100 °C for 10 minutes to obtain the 2PACz layer.

[0138] (3) Accurately weigh 0.13747 g of formamidinium hydrobromide (FABr), 0.36701 g of lead bromide (PbBr 2 ), 0.00123 g of potassium 3-sulfopropyl methacrylate (SPM), 0.85 mL of dimethyl sulfoxide (DMSO), and 0.15 mL of N,N-dimethylformamide (DMF) into a glass bottle, and stir overnight at room temperature to fully dissolve the solutes to obtain a perovskite precursor solution.

[0139] (4) Drop the perovskite precursor solution prepared in step (3) on the 2PACz layer prepared in step (2), first spin-coat it at a speed of 500 rpm for 5 seconds, then spin-coat it at a speed of 4000 rpm for 20 seconds, and add 120 μL of a chloroform / ethyl acetate (v / v = 3:1) mixed solvent 10 seconds before the end of the second spin-coating step, and anneal it at 90 °C for 10 minutes to obtain the perovskite layer.

[0140] (5) Evaporate 5 nm of B4PYMPM, 5 nm of B4PYMPM:C60 (v / v = 0.5:1), 20 nm of C 60 , 5 nm of BCP, and 100 nm of Ag electrode layer by layer on the perovskite layer prepared in step (4) by vacuum thermal evaporation to obtain the optoelectronic conversion device of this example.

[0141] Comparative Example 1

[0142] This comparative example provides an optoelectronic conversion device, which sequentially includes, from bottom to top: an ITO electrode layer (180 nm); a hole transport composite layer composed of a first hole transport layer (NiO x , 15 nm) and a second hole transport layer (2PACz, about 1 nm) stacked in sequence; a three-dimensional perovskite FAPbBr 3 layer (270 nm); a first electron transport layer (C 60 , 20 nm) and a second electron transport layer (BCP, 5 nm) stacked in sequence to form an electron transport composite layer; a silver electrode layer (100 nm). The specific preparation process of the above device is as follows:

[0143] (1) Prepare a 0.1 mol / L nickel acetate tetrahydrate ethanol solution, and add 0.1 mol / L ethanolamine to obtain a NiO x precursor solution. Drop the NiO x precursor solution on the ITO substrate, spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 360 °C for 60 minutes to obtain the NiO x layer.

[0144] (2) Prepare a 0.5 mg / mL 2PACz ethanol solution. Drop the 2PACz ethanol solution on the NiO x layer prepared in step (2), spin-coat it at a speed of 4000 rpm for 30 seconds, and anneal it at 100 °C for 10 minutes to obtain the 2PACz layer.

[0145] (3) Accurately weigh 0.13747 g of formamidinium hydrobromide (FABr), 0.36701 g of lead bromide (PbBr 2 ), 0.00123 g of potassium 3-sulfopropyl methacrylate (SPM), 0.85 mL of dimethyl sulfoxide (DMSO), and 0.15 mL of N,N-dimethylformamide (DMF) into a glass bottle, and stir overnight at room temperature to fully dissolve the solutes to obtain a perovskite precursor solution.

[0146] (4) Drop the perovskite precursor solution prepared in step (3) on the 2PACz layer prepared in step (2), first spin-coat it at a speed of 500 rpm for 5 seconds, then spin-coat it at a speed of 4000 rpm for 20 seconds, and add 120 μL of a chloroform / ethyl acetate (v / v = 3:1) mixed solvent 10 seconds before the end of the second spin-coating step, and anneal it at 90 °C for 10 minutes to obtain the perovskite layer.

[0147] (5) Evaporate 20 nm of C 60 , 5 nm of BCP, and 100 nm of Ag electrode layer by layer on the perovskite layer prepared in step (4) through vacuum thermal evaporation to obtain the optoelectronic conversion device of this comparative example.

[0148] Performance Test

[0149] 1) Test the ultraviolet-visible absorption spectrum and steady-state fluorescence spectrum of the FAPbBr perovskite layer in Example 1 of the present invention. The test results are shown in 3 and Figure 3 respectively. It can be seen from Figure 4 that the perovskite layer has obvious absorption peaks of three-dimensional perovskite, can absorb visible light below 530 nm, and thus excite the carriers in the perovskite layer. It can be seen from Figure 3 that the perovskite layer exhibits a single photoluminescence peak (specifically green light) under ultraviolet light illumination. Therefore, the perovskite material in the embodiments of the present invention has good absorption and luminescence characteristics, which is beneficial to the realization of efficient perovskite photovoltaic-luminescent dual-functional devices. Figure 4

[0150] 2) Test the scanning electron microscope image of the FAPbBr perovskite layer in Example 1 of the present invention. The test result is shown in 3 and the test scale is 1 μm. It can be seen from Figure 5 that the perovskite film exhibits a uniform film morphology and particle size distribution. Figure 5

[0151] 3) Test the photovoltaic performance of the devices in Examples 1-2 and Comparative Example 1. The test results are shown in Table 1 and Figure 6 respectively. The test was carried out under a solar simulator with an illumination intensity of AM1.5G. It can be seen from Table 1 and Figure 5 that compared with Comparative Example 1 using C 60 / BCP as the electron transport combination layer, the open-circuit voltage of the device with B4PYMPM / C 60 / BCP as the electron transport combination layer in Example 1 was significantly increased from 1.22 V to 1.67 V, indicating that the B4PYMPM / C 60 / BCP structure better matches the energy level of the FAPbBr 3 perovskite layer, thus reducing the open-circuit voltage loss. Further, in Example 2, a hybrid layer was introduced between B4PYMPM and C 60 , which can further optimize the device energy level structure and improve the device performance. The open-circuit voltage of the perovskite dual-functional device with B4PYMPM / B4PYMPM:C 60 / C 60 / BCP as the electron transport combination layer in Example 2 was 1.76 V, the short-circuit current density was 7.50 mA·cm -2 , the fill factor was 48.94%, and the photoelectric conversion efficiency was 6.47%.

[0152] It can be seen that in Examples 1-2 of the present invention, by regulating the electron transport layer and the hole transport layer to make them match the FAPbBr 3 ​​The perovskite layer has a more matched energy level structure and energy level arrangement, which can effectively optimize the device performance, achieve a high open-circuit voltage of 1.76 V, and maintain good charge extraction ability, realizing a photoelectric conversion efficiency exceeding 5%.

[0153] Table 1. Photovoltaic performance parameters of the devices in Examples 1-2 and Comparative Example 1

[0154]

[0155] 4) Test the electroluminescence performance of the devices in Examples 1-2 and Comparative Example 1. The performance parameters of each device are shown in Table 2, and the brightness-voltage curve is as Figure 7 shown, and the external quantum efficiency-brightness curve is as Figure 8 shown. The electroluminescence spectrum of the device in Example 2 under different bias voltages is as Figure 9 shown. From Table 2 and Figure 7 it can be seen that the device with C 60 / BCP as the electron transport combined layer cannot emit light under external voltage drive, while in Example 1, a layer of B4PYMPM is introduced between the perovskite and C 60 , and the electroluminescence of the device can be realized, with a maximum brightness of up to 7802 cd·m -2 , and the turn-on voltage as low as 1.8 V, indicating that electrons and holes are injected into the perovskite layer and effective radiative recombination occurs. Further, in Example 2, a hybrid layer is introduced between B4PYMPM and C 60 , which can optimize the energy level structure of the device. The maximum brightness of the device can be significantly increased to 28520 cd·m -2 , and the external quantum efficiency gradually increases with the increase of brightness, with a maximum external quantum efficiency of 1.26%. From Figure 8 it can be seen that the perovskite bifunctional device in Example 2 has a stable electroluminescence spectrum under different bias voltages, with a peak value of 540 nm, located in the visible light band.

[0156] It can be seen that in Examples 1-2 of the present invention, by regulating the electron transport layer and the hole transport layer, making their energy level structure and energy level arrangement more matched with the FAPbBr 3 perovskite layer, the obtained device can have both photovoltaic and luminescent characteristics, can sensitively respond to optical signals, generate electricity efficiently under illumination, and emit light with low energy consumption in the dark, having an efficient application effect.

[0157] Table 2. Electroluminescence performance parameters of the devices in Examples 1-2 and Comparative Example 1

[0158]

[0159] In summary, the optoelectronic reversible conversion dual-functional device provided by the present application is simple to prepare and low in cost. The hole transport composite layer and the electron transport composite layer structures used in the device structure can match the energy levels of the perovskite layer, thereby balancing the charge extraction and injection in the perovskite material. The free electrons and holes generated by the perovskite material under light illumination can be extracted by the electron transport layer and the hole transport layer respectively. Under the action of an external bias voltage, the device can inject electrons and holes into the perovskite layer through the electron transport composite layer and the hole transport composite layer for radiative recombination, so that the device can achieve dual functions of photovoltaics and light emission under different working mechanisms, and the emission wavelength is within the visible light range. Therefore, the dual-functional device in the present invention can be widely applied to fields such as photovoltaics, lighting, and display.

[0160] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the described embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A photoelectric conversion device, characterized in that: It includes a first electrode, a hole transport layer, a semiconductor functional layer, an electron transport layer, and a second electrode which are stacked in sequence; The conduction band energy level of the electron transport layer matches the conduction band energy level of the semiconductor functional layer; the valence band energy level of the electron transport layer is deeper than the valence band energy level of the semiconductor functional layer; The valence band energy level of the hole transport layer matches the valence band energy level of the semiconductor functional layer; and the conduction band energy level of the hole transport layer is shallower than the conduction band energy level of the semiconductor functional layer.

2. The photoelectric conversion device according to claim 1, characterized in that: The semiconductor functional layer includes a direct bandgap semiconductor material; the direct bandgap semiconductor material includes at least one of metal halide perovskite, gallium nitride, cadmium selenide or indium phosphide.

3. The optical-to-electrical conversion device according to claim 2, characterized in that: The chemical formula of the metal halide perovskite is AMX3 or L2A n-1 M n X 3n+1 ; Wherein, A represents a monovalent cation, and A includes Cs + , Rb + 、MA + , FA + or GA + At least one of; M represents a divalent cation, M includes Pb 2+ Sn 2+ , Mn 2+ , Ca 2+ or Zn 2+ At least one of; X represents a monovalent anion, X includes F - , Cl - Br - ,I - 、(BF4) - or SCN - At least one of; L represents a monovalent cation, L includes EA + ,PA + 、i-PA + BA + 、i-BA + , t-BA + , HA + OA + , Ph.A. + 、PMA + 、PEA + 、PPA + or NMA + At least one of; n is 1 to 10.

4. The photoelectric conversion device according to claim 1, characterized in that: The electron transport layer comprises at least one of the following layer structures: a first electron single layer structure consisting of a first electron transport layer; a second electron multilayer structure consisting of a first electron transport layer and a second electron transport layer stacked in layers; a third electron multilayer structure consisting of a first electron transport layer, a second electron transport layer and a third electron transport layer stacked in sequence; a fourth electron multilayer structure consisting of a first electron transport layer, a mixed electron transport layer, a second electron transport layer and a third electron transport layer stacked in sequence; Wherein, the first electron transport layer, the second electron transport layer, and the third electron transport layer each independently include at least one electron transport material; and the mixed electron transport layer includes at least two electron transport materials.

5. The optical-to-electrical conversion device according to claim 1, characterized in that: The electron transport layer includes an electron transport material; the electron transport material includes 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine, 4,6-bis(3,5-di(3-pyridyl)phenyl)-2-methylpyrimidine, 4,6-bis(3,5-di(4-pyridyl)phenyl)-2-methylpyrimidine, tris[2,4,6-trimethyl-3-(3-pyridyl)phenyl]borane, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, fullerene C 60 , Fullerene C 70 ,[6,6]-phenyl C 61 At least one of methyl butyrate, [6,6]-phenyl C71 butyrate, 2,7-bis(3-(dimethylamino)propyl)benzo[LMN][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone, zinc oxide or tin dioxide.

6. The photoelectric conversion device according to claim 1, characterized in that: The hole transport layer comprises at least one of the following layer structures: a first hole single layer structure consisting of a first hole transport layer; a second hole multilayer structure consisting of a first hole transport layer and a second hole transport layer stacked; Wherein, the first hole transport layer and the second hole transport layer each independently include at least one hole transport material.

7. The photoelectric conversion device according to claim 1, characterized in that: The hole transport layer includes a hole transport material; the hole transport material includes polyethylene dioxythiophene-poly(styrene sulfonate), nickel oxide, molybdenum trioxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(9-vinylcarbazole), poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butyl)phenyl)-diphenylamine)], 2,2',7,7'-tetra[N,N -bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, [2-(9H-carbazole-9-yl)ethyl]phosphate, [4-(9H-carbazole-9-yl)butyl]phosphate, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphate, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphate or [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate.

8. The photoelectric conversion device according to claim 1, characterized in that: The thickness of the first electrode is 1 to 200 nm; and / or, the thickness of the hole transport layer is 0.5 to 30 nm; And / or, the thickness of the semiconductor functional layer is 50 to 2000 nm; And / or, the thickness of the electron transport layer is 0.5 to 100 nm; And / or, the thickness of the second electrode is 1-200 nm.

9. A method for preparing a photoelectric conversion device according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: preparing the first electrode, the hole transport layer, the semiconductor functional layer, the electron transport layer and the second electrode in sequence to obtain the photoelectric conversion device.

10. A light-to-electricity conversion device, characterized in that: The invention comprises the photoelectric conversion device according to any one of claims 1 to 8.

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