Operation control method and system for perovskite solar cell

Abstract

The present disclosure provides an operation control method and system for a perovskite solar cell. The method comprises: measuring the photovoltage of a perovskite solar cell; and when the photovoltage is smaller than a preset photovoltage threshold, applying a bias voltage to the perovskite solar cell.

Description

Method and system for operating perovskite solar cell

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202410457938.X, filed on April 16, 2024, entitled "Method and system for operating perovskite solar cell", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of batteries, and in particular to a method and system for operating a perovskite solar cell. BACKGROUND

[0004] In recent years, global energy shortages and environmental pollution problems have become increasingly prominent, and solar cells, as an ideal renewable energy source, have received increasing attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through photoelectric or photochemical effects.

[0005] As a new photovoltaic technology for the future, perovskite solar cells have made remarkable progress, however, due to the migration of ions in perovskite materials, the long-term operation stability of perovskite solar cells is poor, and it is not conducive to the long-term operation of perovskite solar cells. SUMMARY

[0006] The present disclosure is made in view of the above-mentioned problems, and aims to provide a method and system for operating a perovskite solar cell, which can improve the operation stability and total power generation of the perovskite solar cell.

[0007] To achieve the above-mentioned purpose, the first aspect of the present disclosure provides a method for operating a perovskite solar cell, the method comprising: detecting the photovoltage of the perovskite solar cell; and applying a bias voltage to the perovskite solar cell if the photovoltage is less than a preset photovoltage threshold. In the present disclosure, by applying a bias voltage to the perovskite solar cell, the ions accumulated at the interface between the charge transport layer and the light absorbing layer in the perovskite solar cell can be returned to the initial position in the light absorbing layer, thus, the ion migration phenomenon in the light absorbing layer can be inhibited, and the stability and total power generation of the perovskite solar cell can be effectively improved.

[0008] In some embodiments, the voltage range of the bias voltage is x*V OC to y*V OC wherein x is -1 to 0; y is 1 to 4; and V OCThe initial open circuit voltage of the perovskite solar cell. In the present disclosure, the voltage range of the bias voltage is within the above range, which can make the cations accumulated at the interface between the hole transport layer and the light absorbing layer and the anions accumulated at the interface between the electron transport layer and the light absorbing layer move in different directions and finally return to the initial positions in the light absorbing layer, thereby effectively improving the stability and total power generation of the perovskite solar cell.

[0009] In some embodiments, the voltage range of the bias voltage is x*V OC to y*V OC , wherein x is -1-0; y is 2-4. In some embodiments, the voltage range of the bias voltage is -1*V OC to 2*V OC , V OC is the initial open circuit voltage of the perovskite solar cell. In the present disclosure, the voltage range of the bias voltage is within the above range, which can make the cations and anions accumulated at the interface of the light absorbing layer move in different directions and finally return to the initial positions in the light absorbing layer, thereby effectively improving the stability and total power generation of the perovskite solar cell.

[0010] In some embodiments, the bias voltage applied to the perovskite solar cell is an alternating voltage. In the present disclosure, by setting the bias voltage as an alternating voltage, the direction and speed of ion migration can be variable, which can better control the direction and speed of ion migration and make the migrated cations and anions return to the initial positions in the light absorbing layer.

[0011] In some embodiments, in the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied in the scanning direction of forward scanning and / or reverse scanning. In the present disclosure, the bias voltage is applied in different scanning directions for different perovskite solar cells, which can improve the ion migration phenomenon in the perovskite solar cell in a targeted manner and be beneficial to improving the stability and total power generation of the perovskite solar cell.

[0012] In some embodiments, in the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied at a voltage change rate of 50 mV / s to 1500 mV / s. In the present disclosure, by applying the bias voltage to the perovskite at a voltage change rate within the above range, the operating stability and total power generation of the perovskite solar cell can be improved without adversely affecting the perovskite solar cell device.

[0013] In some embodiments, the bias voltage is applied at a voltage change rate of 200 mV / s to 400 mV / s in the case of applying the bias voltage in the scanning direction of reverse scanning or forward scanning; the voltage change rate of the bias voltage is 50 mV / s to 500 mV / s in the case of applying the bias voltage in the scanning direction of reverse scanning and forward scanning. In the present disclosure, by applying the bias voltage with different voltage change rates to the perovskite solar cell, the influence of the bias voltage on the ion migration species and speed can be controlled, so that the anions and cations accumulated at the interface between the transport layer and the light-absorbing layer can be better returned to the initial position in the light-absorbing layer, and finally the stability and total power generation of the perovskite solar cell can be improved.

[0014] In some embodiments, the bias voltage applied to the perovskite solar cell includes periodically applying the bias voltage to the perovskite solar cell. In the present disclosure, by periodically applying the bias voltage to the perovskite solar cell, the ion migration phenomenon of the perovskite solar cell can be improved better, which is more conducive to improving the stability and total power generation of the perovskite solar cell.

[0015] In some embodiments, the period of applying the bias voltage to the perovskite solar cell is 1 minute to 12 hours. In some embodiments, the period of applying the bias voltage to the perovskite solar cell is 0.5 hours to 4 hours.

[0016] In some embodiments, in the case that the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.95*PCE0, the period of applying the bias voltage to the perovskite solar cell is 3 hours to 12 hours; in the case that the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.9*PCE0 and less than 0.95*PCE0, the period of applying the bias voltage to the perovskite solar cell is 2 hours to 4 hours; in the case that the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.8*PCE0 and less than 0.9*PCE0, the period of applying the bias voltage to the perovskite solar cell is 1 hour to 2 hours; in the case that the photoelectric conversion efficiency of the perovskite solar cell is less than 0.8*PCE0, the period of applying the bias voltage to the perovskite solar cell is 0.5 hours to 1 hour; PCE0 is the photoelectric conversion efficiency of the perovskite solar cell measured under AM1.5G spectrum irradiation at 25℃, 100 mW cm -2 The photoelectric conversion efficiency of the perovskite solar cell measured under AM1.5G spectrum irradiation at an irradiation intensity. In the present disclosure, different periods of applying the bias voltage are selected according to the degree of decrease in the photoelectric conversion efficiency of the perovskite solar cell, which can make the ion migration phenomenon of the perovskite solar cell improve more obviously, and is more conducive to improving the stability and total power generation of the perovskite solar cell.

[0017] In some embodiments, the operation control method of the perovskite solar cell is applied to a perovskite solar cell with a photoelectric conversion efficiency less than 0.95*PCE0; PCE0 is the photoelectric conversion efficiency of the perovskite solar cell measured at 25℃, 100mW cm -2 The photoelectric conversion efficiency of the perovskite solar cell measured when irradiated under AM1.5G spectrum with an irradiation intensity of 100mW cm-2.

[0018] In some embodiments, the preset photovoltage threshold is 0-0.6*V OC ; V OC is the initial open-circuit voltage of the perovskite solar cell.

[0019] The second aspect of the present disclosure provides a perovskite solar cell operation control system, comprising: a detection unit for detecting the photovoltage of the perovskite solar cell; a voltage source; a control module connected with the voltage source, for controlling the voltage source to apply a bias to the perovskite solar cell when the photovoltage of the perovskite solar cell is detected to be less than a preset photovoltage threshold. The perovskite solar cell operation control system in the present disclosure can apply a bias to the perovskite solar cell when the photovoltage of the perovskite solar cell is less than the preset photovoltage threshold, so that the ions accumulated at the interface between the charge transport layer and the light-absorbing layer in the perovskite solar cell return to the initial position in the light-absorbing layer, which is beneficial to improve the stability and total power generation of the perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a flowchart of the operation control method of the perovskite solar cell provided by an embodiment of the present disclosure.

[0021] Fig. 2 is a schematic structural diagram of the perovskite solar cell provided by an embodiment of the present disclosure.

[0022] Fig. 3 is a schematic structural diagram of the perovskite solar cell operation control system provided by an embodiment of the present disclosure.

[0023] Fig. 4 is a schematic diagram of the ion movement in the light-absorbing layer of the perovskite solar cell during operation of the perovskite solar cell provided by an embodiment of the present disclosure.

[0024] Fig. 5 is a current density-voltage characteristic curve of the perovskite solar cell in Example 1 of the present disclosure.

[0025] Fig. 6 is a comparison diagram of the light-dark cyclic steady-state power output of the perovskite solar cells in Example 23, Example 24 and Comparative Example 2 of the present disclosure under simulated real working conditions.

[0026] Explanation of reference signs:

[0027] perovskite solar cell 20; first electrode 201; second electrode 205; light-absorbing layer 203; hole transport layer 202; electron transport layer 204;

[0028] A perovskite solar cell operation control system 30; a control device 40; a control module 401; a power control device 402; a voltage source 403. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of a perovskite solar cell operation control method according to the present disclosure are specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there can be cases where unnecessary detailed descriptions are omitted. For example, there can be cases where detailed descriptions of matters that are well known, repeated descriptions of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided so that those skilled in the art can fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0030] The "ranges" disclosed in the present disclosure are defined in the form of lower and upper limits, and a given range is defined by selecting one lower limit and one upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present disclosure, unless otherwise specified, a numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when it is stated that a certain parameter is an integer ≥ 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0031] Unless otherwise specified, all embodiments of the present disclosure and optional embodiments can be combined with each other to form new technical solutions.

[0032] Unless otherwise specified, all technical features of the present disclosure and optional technical features can be combined with each other to form new technical solutions.

[0033] If not otherwise specified, all steps of the present disclosure can be carried out in sequence or randomly, preferably in sequence. For example, a method comprising steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any sequence, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0034] If not otherwise specified, the terms used in the present disclosure have the commonly understood meanings by those skilled in the art.

[0035] If not otherwise specified, the values of the parameters mentioned in the present disclosure can be determined by various test methods commonly used in the art, for example, by the test methods given in the present disclosure.

[0036] As a new type of photovoltaic technology for the future, perovskite solar cells have made remarkable progress, however, the long-term operation stability of perovskite solar cells is poor, and the T80 lifetime (the photoelectric conversion efficiency decays to 80% of the initial value) of the most advanced perovskite solar cells currently operating under environmental conditions is only a few thousand hours, which is still short compared with the actual commercial crystalline silicon solar cells, which will seriously limit the commercialization process of perovskite photovoltaics.

[0037] In addition, the intrinsic instability of perovskite materials is still a major obstacle to limiting the operation life of perovskite solar cells. As a soft ionic crystal, perovskite materials are prone to ion migration, especially during actual operation, under light, the ions in the perovskite layer (i.e. the light absorbing layer) will migrate directionally and accumulate at the interface due to the built-in electric field induction, among which the anions migrate to the side of the electron transport layer, and the cations migrate to the side of the hole transport layer. Ion migration in the perovskite layer not only affects the transport and extraction of carriers, affecting the device efficiency of perovskite solar cells, but also destroys the perovskite crystal structure, ultimately leading to poor long-term stability of perovskite solar cell devices.

[0038] More importantly, the ion migration phenomenon of the perovskite layer not only causes the efficiency of the perovskite solar cell device to decay, but also is not conducive to the long-term power generation of the perovskite solar cell device. Specifically, in the actual operation condition of the perovskite solar cell, there is a day-night alternation. Studies have shown that under dark conditions, ion migration may be partially restored, and the type of defect state may also change, resulting in a series of complex metastable behaviors. Therefore, the perovskite solar cell device will exhibit a "fatigue" phenomenon in the day-night alternation cycle. When the perovskite solar cell is exposed to light again, its photoelectric conversion efficiency will be lower than the maximum value, and it will take several hours to recover to the maximum value, and the recovery time will significantly increase with the increase of the number of day-night alternation. This "fatigue" phenomenon will cause the maximum output power of the perovskite solar cell device to decrease, seriously affecting the continuous power generation of the perovskite solar cell, and there is currently a lack of methods to inhibit the "fatigue" phenomenon. Therefore, how to inhibit the ion migration and "fatigue" phenomenon in the perovskite solar cell device and maintain the efficiency and stable maximum output power of the perovskite solar cell is a problem to be solved at present.

[0039] Based on this, the embodiments of the present disclosure provide a new method for controlling the operation of a perovskite solar cell, which can inhibit and alleviate the ion migration and "fatigue" behavior of the perovskite solar cell during operation, thereby alleviating or eliminating the adverse effects of ion migration behavior in the perovskite on the perovskite solar cell, and facilitating to improve the operation stability and total power generation of the perovskite solar cell.

[0040] The embodiments of the present disclosure provide a method for controlling the operation of a perovskite solar cell. FIG. 1 is a flowchart of the method for controlling the operation of a perovskite solar cell according to an embodiment of the present disclosure. As shown in FIG. 1, the method for controlling the operation of a perovskite solar cell includes the following steps:

[0041] In step S101, the photovoltage of the perovskite solar cell is detected.

[0042] In step S102, a bias voltage is applied to the perovskite solar cell when the photovoltage is less than a preset photovoltage threshold.

[0043] In the present disclosure, by applying a bias voltage to the perovskite solar cell, the ions accumulated at the interface between the charge transport layer and the light absorbing layer in the perovskite solar cell can be returned to the light absorbing layer.

[0044] Under light illumination, ions in the perovskite layer (i.e. light absorbing layer) of the perovskite solar cell will migrate directionally and accumulate at the interface between the charge transport layer and the light absorbing layer due to the built-in electric field. This ion migration phenomenon cannot be completely restored when the perovskite solar cell is in the dark state (i.e. non-working state), so the perovskite solar cell device will show a maximum output power drop in the day-night alternating cycle, which seriously affects the continuous power generation of the perovskite solar cell. In addition, this ion migration phenomenon will destroy the crystal structure of the perovskite material, which is not conducive to the long-term operation stability of the perovskite solar cell device. In the present disclosure, by applying a bias to the perovskite solar cell when the photovoltage of the perovskite solar cell is less than a preset photovoltage threshold (i.e. dark state condition), the accumulated ions at the interface between the charge transport layer and the light absorbing layer are redistributed by the bias and return to the initial position in the light absorbing layer. In this way, the ion migration phenomenon in the light absorbing layer can be inhibited, and the stability and total power generation of the perovskite solar cell can be effectively improved.

[0045] It should be noted that the operation control method of the perovskite solar cell in the present disclosure preferably applies a bias when the perovskite solar cell has aged to some extent, which is more effective in improving the stability and total power generation, and is more convenient to operate.

[0046] Before introducing the operation control method of the perovskite solar cell in the present disclosure in detail, the structure and working principle of the perovskite solar cell will be introduced first.

[0047] Figure 2 shows a schematic diagram of the structure of a perovskite solar cell. As shown in Figure 2, the perovskite solar cell 20 includes a first electrode 201, a light absorbing layer 203, a charge transport layer, and a second electrode 205, wherein the charge transport layer includes a hole transport layer 202 and an electron transport layer 204. The hole transport layer 202 is located between the first electrode 201 and the light absorbing layer 203, and the electron transport layer 204 is located between the light absorbing layer 203 and the second electrode 205, forming a perovskite solar cell with an inverted structure (P-I-N type). The photoelectric conversion principle of the perovskite solar cell is as follows: after the incident light (e.g. sunlight) enters the device from the first electrode 201 and reaches the light absorbing layer 203, it is absorbed by the light absorbing layer. Under the excitation of the incident light, the light absorbing layer 203 generates hole-electron pairs, and under the action of the electric field, the holes and electrons are separated. The electrons are transported to the second electrode 205 through the electron transport layer 204, and the holes are transported to the first electrode 201 through the hole transport layer 202. Subsequently, a loop is formed through the external circuit, which can be used to drive the load to work.

[0048] In some embodiments, the positions of the electron transport layer 204 and the hole transport layer 202 in the above-mentioned Figure 2 can be interchanged, forming a perovskite solar cell with a normal structure (N-I-P type).

[0049] The first electrode 201 is a bottom electrode of the perovskite solar cell device, and the second electrode 205 is a top electrode of the perovskite solar cell device. The bottom electrode refers to the electrode that first receives incident light, and the top electrode refers to the electrode that last receives incident light.

[0050] In some embodiments, the material adopted by the bottom electrode includes a transparent conductive material. The present disclosure does not have a particular limitation on the transparent conductive material included by the bottom electrode. Illustratively, the transparent conductive material includes at least one of indium tin oxide (ITO), indium tin oxide, fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide, and indium-doped tungsten oxide. The material adopted by the top electrode includes a conductive material. The present disclosure does not have a particular limitation on the conductive material included by the top electrode. For example, the conductive material includes at least one of an organic conductive material, an inorganic conductive material, and a carbon elemental material, wherein the inorganic conductive material includes at least one of the above-mentioned transparent conductive oxide material, a metal and an alloy thereof, and the carbon elemental material. Illustratively, the metal and the alloy thereof include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, and tungsten. Illustratively, the carbon elemental material includes at least one of graphite, graphene, and carbon nanotube.

[0051] The light-absorbing layer 203 is capable of generating electron-hole pairs based on the excitation of incident light. The present disclosure does not have a particular limitation on the band gap of the light-absorbing layer 203, and the band gap of the light-absorbing layer 203 adopted in the art can be used. Illustratively, the band gap of the light-absorbing layer 203 is in the range of 1.20 eV to 2.30 eV. In the present disclosure, the method for measuring the band gap is not particularly limited. Illustratively, the method for measuring the band gap can include: first, obtaining an ultraviolet absorption curve by ultraviolet absorption spectrum test; and then calculating the band gap of the perovskite light-absorbing layer 203 by Tauc equation. The present disclosure does not have a particular limitation on the thickness of the light-absorbing layer 203, and the thickness of the light-absorbing layer 203 adopted in the art can be used. Illustratively, the perovskite thickness is in the range of 400 nm to 1000 nm.

[0052] The light-absorbing layer 203 is made of a perovskite material with a chemical formula of ABX3 or A2CDX6. Wherein, A includes at least one of inorganic or organic monovalent cations, B includes at least one inorganic divalent cation, C includes at least one inorganic monovalent cation, D includes at least one inorganic trivalent cation, and X includes at least one monovalent anion. Illustratively, A includes formamidinium cation (abbreviated as FA + ), methylamine cation (abbreviated as MA + ), or cesium cation (abbreviated as Cs +) and B includes at least one of a lead cation or a tin cation; C includes a silver cation; D includes at least one of a bismuth cation, an indium cation or an antimony cation, and X includes at least one of an iodine ion, a bromine ion or a chlorine ion. Due to the existence of defects and impurities at the grain boundaries of the perovskite material, these defects and impurities affect the electronic structure and the band structure at the grain boundaries, so that the B (or C, or D) cation and the X anion in the perovskite material ABX3 or A2CDX6 are not tightly combined, and the X anion is prone to wander in the perovskite material, resulting in poor stability of the perovskite material. Therefore, under the induction of the built-in electric field of the perovskite solar cell, the B (or C, or D) cation and the X anion in the light-absorbing layer 203 are prone to ion migration, specifically, the B (or C, or D) cation migrates to the side of the hole transport layer 202, and the X anion migrates to the side of the electron transport layer 204, resulting in ion accumulation.

[0053] The electron transport layer 204 has the function of transporting electrons, and is used to transport the electrons generated by the excitation of the light-absorbing layer 203 to the second electrode 205. The electron transport material used by the present disclosure for the electron transport layer is not specifically limited, and the electron transport material commonly used in the art can be used. For example, the electron transport material includes at least one of an imide compound, a quinone compound, a fullerene and a derivative thereof, a metal oxide, a semiconductor material oxide, a titanate, a fluoride and a derivative thereof, and a material obtained by doping or passivation thereof. For example, the imide compound includes at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide. For example, the quinone compound includes at least one of benzoquinone, naphthoquinone, phenanthraquinone or anthraquinone. For example, the fullerene and the derivative thereof include at least one of fullerene C 60 , fullerene C 70、 PC 61 BM([6,6]-phenyl-C61-butyric acid methyl ester), [6,6]-phenyl C 71 butyric acid methyl ester (PC 71 BM). For example, the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr, and optionally, the metal oxide includes at least one of tin dioxide (SnO2) and zinc oxide (ZnO). For example, the semiconductor material oxide includes silicon oxide. For example, the titanate includes at least one of strontium titanate and calcium titanate. For example, the fluoride includes at least one of lithium fluoride and calcium fluoride.

[0054] The hole transport layer 202 has a function of transporting holes, and is used to transport the holes generated by the light absorption layer 203 to the first electrode 201. The hole transport material used in the hole transport layer is not specifically limited in the present disclosure, and the hole transport material commonly used in the art can be used. For example, the hole transport material includes at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), poly-3-hexylthiophene (P3HT), triphenylamine (H101) with triptycene as the core, 3,4-ethylenedioxythiophene-methoxy triphenylamine (EDOT-OMeTPA), N-(4-aminophenyl)carbazole-spirobifluorene (CzPAF-SBF), poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS), polythiophene, nickel oxide (NiOx), molybdenum trioxide (MoO3), cuprous iodide (CuI), cuprous oxide (CuO), [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), and [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz).

[0055] In some embodiments, the perovskite solar cell further comprises an interface modification layer, which can be used to modify the hole transport layer 202 or the electron transport layer 204. The interface modification layer used to modify the hole transport layer 202 can be a carbazole derivative-MXene.

[0056] In some embodiments, the perovskite solar cell can also be a stacked cell containing a perovskite cell, such as a perovskite-crystalline silicon stacked cell, a perovskite-perovskite stacked cell, or other stacked cells that can be stacked with perovskite.

[0057] In some embodiments, the step of detecting the photovoltage of the perovskite solar cell in step S101 can be achieved by a photocurrent density-photovoltage (J-V) test. For example, the photovoltage of the perovskite solar cell can be measured by a Keithley 2400 digital source meter under an AM1.5G solar simulator.

[0058] In some embodiments, the step of detecting the photovoltage of the perovskite solar cell in step S101 can also be achieved by a multimeter, a photoelectric sensor, or a photovoltaic inverter.

[0059] In some embodiments, the photovoltage of the perovskite solar cell can be determined according to the working state of the perovskite solar cell, for example, when the perovskite solar cell is in a dark state, the photovoltage of the perovskite solar cell is determined to be 0 V.

[0060] In some embodiments, the preset photovoltage threshold value can be 0~0.6*V OC (V OC herein refers to the initial open-circuit voltage of the perovskite solar cell tested under standard test conditions, i.e., 25℃, 100mW cm -2 irradiance under AM1.5G spectrum), and exemplarily, the preset photovoltage threshold value can be 0.5*V OC When the photovoltage of the perovskite solar cell is greater than or equal to the preset photovoltage threshold value, the perovskite solar cell is in the light state (i.e., working state), and when the photovoltage of the perovskite solar cell is less than the preset photovoltage threshold value, the perovskite solar cell is in the dark state (i.e., non-working state). When the perovskite solar cell is in the light state, due to the induction of the built-in electric field, the cations in the light-absorbing layer are easy to migrate to the side of the hole transport layer and accumulate at the interface between the hole transport layer and the light-absorbing layer, and the anions in the light-absorbing layer are easy to migrate to the side of the electron transport layer and accumulate at the interface between the electron transport layer and the light-absorbing layer. This ion migration phenomenon not only is not conducive to the long-term operation stability of the perovskite solar cell device, but also affects the long-term operation power generation of the perovskite solar cell device. In the present disclosure, by additionally applying a bias voltage in the dark state, the accumulated cations at the interface between the hole transport layer and the light-absorbing layer and the accumulated anions at the interface between the electron transport layer and the light-absorbing layer can be induced to return to the light-absorbing layer, which can effectively improve the stability and total power generation of the perovskite solar cell.

[0061] In some embodiments, the voltage range of the bias voltage is x*V OC to y*V OC , wherein x is -1~0, and y is 1~4; optionally, x is -1~0, and y is 2~4. Further optionally, the voltage range of the bias voltage is -1*V OC to 2*V OC , V OC is the initial open-circuit voltage of the perovskite solar cell. In the present disclosure, the voltage range of the bias voltage is within the above range, which can make the accumulated cations at the interface between the hole transport layer and the light-absorbing layer and the accumulated anions at the interface between the electron transport layer and the light-absorbing layer move in different directions and finally return to the initial position in the light-absorbing layer without breaking through the structure of the perovskite solar cell device, which can effectively improve the stability and total power generation of the perovskite solar cell.

[0062] In some embodiments, the initial open-circuit voltage V OC is the maximum output voltage of the perovskite solar cell under standard test conditions (25℃, 100mW cm -2 irradiance under AM1.5G spectrum).

[0063] In some embodiments, the bias voltage applied to the perovskite solar cell is an alternating voltage, and the magnitude and direction of the applied bias voltage are varied. In the present disclosure, by setting the bias voltage as an alternating voltage, the direction and speed of ion migration can be varied, and the direction and speed of ion migration can be better controlled, so that the migrated cations and anions can return to the initial positions in the light-absorbing layer.

[0064] In some embodiments, in the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied in a forward scan and / or a reverse scan. Specifically, the forward scan refers to the applied voltage gradually changes from a negative voltage to a positive voltage at a certain voltage change rate, and the reverse scan refers to the applied voltage gradually changes from a positive voltage to a negative voltage at a certain voltage change rate. For example, when the bias voltage is applied in a voltage range from -1*Voc to +2*Voc (where Voc represents the initial open circuit voltage of the perovskite solar cell, i.e., the open circuit voltage before aging), the reverse scan is from +2*Voc to -1*Voc, and the forward scan is from -1*Voc to +2*Voc. In the present disclosure, different scan directions are applied to different perovskite solar cells, which can improve the ion migration phenomenon in the perovskite solar cell in a targeted manner, and is beneficial to improving the stability and total power generation of the perovskite solar cell.

[0065] In some embodiments, the scan direction of the bias voltage applied to the perovskite solar cell includes a forward scan. In some embodiments, the scan direction of the bias voltage applied to the perovskite solar cell includes a reverse scan. In some embodiments, the scan direction of the bias voltage applied to the perovskite solar cell includes a forward scan and a reverse scan.

[0066] In some embodiments, the scan direction of the bias voltage applied to the perovskite solar cell includes a forward scan first and then a reverse scan.

[0067] In some embodiments, the scan direction of the bias voltage applied to the perovskite solar cell includes a reverse scan first and then a forward scan.

[0068] In some embodiments, in the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied at a voltage change rate of 50 mV / s to 1500 mV / s. In the present disclosure, by applying a bias voltage to the perovskite at a voltage change rate in the above range, the operating stability and total power generation of the perovskite solar cell can be improved without adversely affecting the perovskite solar cell device.

[0069] In some embodiments, the bias voltage is applied at a voltage change rate of 200 mV / s to 400 mV / s in the scan direction of reverse scan or forward scan; in the case of applying the bias voltage in the scan direction of reverse scan and forward scan, the voltage change rate of the bias voltage in the reverse scan process is 50 mV / s to 500 mV / s, and the voltage change rate of the bias voltage in the forward scan process is 300 mV / s to 1000 mV / s. In the present disclosure, by applying bias voltages with different voltage change rates to the perovskite solar cell in different scan directions, the influence of the bias voltage on the ion migration species and speed can be controlled, so that the anions and cations accumulated at the interface between the charge transport layer and the light absorbing layer can be better returned to the initial position in the light absorbing layer, and finally the stability and total power generation of the perovskite solar cell can be improved. Specifically, at a lower voltage change rate, it is beneficial for ions with a slower migration rate (such as B-site cations) to migrate, and at a higher voltage change rate, it is beneficial for ions with a faster migration rate (such as X-site anions) to migrate.

[0070] In some embodiments, the bias voltage applied to the perovskite solar cell includes periodically applying a bias voltage to the perovskite solar cell. In the present disclosure, by periodically applying a bias voltage to the perovskite solar cell, the ion migration phenomenon of the perovskite solar cell can be improved better, which is more conducive to improving the stability and total power generation of the perovskite solar cell. In some embodiments, the period of applying the bias voltage to the perovskite solar cell is 1 minute to 12 hours, and optionally, the period of applying the bias voltage to the perovskite solar cell is 0.5 hours to 3 hours.

[0071] In some embodiments, different periods of applying bias voltage can be selected when the degree of decrease in the photoelectric conversion efficiency of the perovskite solar cell is different. Specifically, when the decrease in the photoelectric conversion efficiency of the perovskite solar cell is small, the interval period of applying bias voltage should be longer, and when the decrease in the photoelectric conversion efficiency of the perovskite solar cell is large, the interval period of applying bias voltage should be shorter, depending on the intrinsic stability of the device. For example, when the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.95*PCE0, the period of applying bias voltage to the perovskite solar cell is 3 hours to 12 hours; when the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.9*PCE0 and less than 0.95*PCE0, the period of applying bias voltage to the perovskite solar cell is 2 hours to 4 hours; when the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.8*PCE0 and less than 0.9*PCE0, the period of applying bias voltage to the perovskite solar cell is 1 hour to 2 hours; when the photoelectric conversion efficiency of the perovskite solar cell is less than 0.8*PCE0, the period of applying bias voltage to the perovskite solar cell is 0.5 hours to 1 hour; and PCE0 herein refers to the PCE under standard conditions, i.e. 25°C, 100 mW cm-2AM1.5G spectrum irradiation intensity. -2 The photoelectric conversion efficiency value measured when irradiated with AM1.5G spectrum at an irradiation intensity. In the present disclosure, the period of applying bias voltage to the perovskite solar cell is set within the above range, which can make the ion migration phenomenon of the perovskite solar cell more obvious, and is more conducive to improving the stability and total power generation of the perovskite solar cell.

[0072] In some embodiments, when the detected photovoltage is greater than a preset photovoltage threshold, the perovskite solar cell is in a light state, and the light energy is converted into electrical energy.

[0073] In some embodiments, the operation control method of the perovskite solar cell described above is optionally applied to a perovskite solar cell with a photoelectric conversion efficiency less than 0.95*PCE0. In this way, the effect of improving the operation stability and total power generation achieved by the present disclosure is better, and the operation is more convenient.

[0074] The operation control method of the perovskite solar cell in the present disclosure is applied to an operation control system of the perovskite solar cell, and another embodiment of the present disclosure provides an operation control system of the perovskite solar cell. FIG. 3 shows a structural schematic diagram of an operation control system of a perovskite solar cell. As shown in FIG. 3, the operation control system 30 of the perovskite solar cell comprises: a detection unit (not shown) for detecting the photovoltage of the perovskite solar cell 20; a voltage source 403; and a control module 401 connected with the voltage source 403, for controlling the voltage source 403 to apply a bias voltage to the perovskite solar cell 20 when the photovoltage of the perovskite solar cell 20 is detected to be less than a preset photovoltage threshold, so that the ions accumulated at the interface between the charge transport layer and the light-absorbing layer 203 in the perovskite solar cell 20 return to the light-absorbing layer 203. In the present disclosure, the operation control system 30 of the perovskite solar cell is used to inhibit and alleviate the ion migration and "fatigue" behavior generated in the perovskite solar cell 20 during operation. The operation control system of the perovskite solar cell in the present disclosure can apply a bias voltage to the perovskite solar cell when the photovoltage of the perovskite solar cell is less than the preset photovoltage threshold, so that the ions accumulated at the interface between the charge transport layer and the light-absorbing layer in the perovskite solar cell return to the initial position in the light-absorbing layer, which is conducive to improving the stability and total power generation of the perovskite solar cell.

[0075] Please continue to refer to FIG. 3. The operation control system 30 of the perovskite solar cell further comprises a power control device 402.

[0076] In some embodiments, the detection unit can be an electrochemical workstation, a multimeter, a photovoltaic inverter or a voltage sensor. The present disclosure does not limit the detection unit, and any device that can detect the photovoltage of the perovskite solar cell 20 belongs to the protection scope of the present disclosure.

[0077] In some embodiments, the control module 401 is connected with the perovskite solar cell 20, the power control device 402 and the voltage source 403, and controls the perovskite solar cell 20 to switch between a normal mode and a bias voltage mode. The normal mode refers to a state in which the perovskite solar cell 20 is connected with the power control device 402 and converts light energy into electrical energy when irradiated. The bias voltage mode refers to a state in which the perovskite solar cell 20 receives a bias voltage applied by the voltage source 403 in a dark state, so as to inhibit and alleviate the ion migration and accumulation generated in the normal mode, restore the performance of the perovskite solar cell device, and make the perovskite solar cell device restore good output power in the next normal mode.

[0078] In some embodiments, the power control device 402 is used to track the maximum power point of the perovskite solar cell 20 in the normal mode, and extract the electrical energy generated by the perovskite solar cell 20 when irradiated and output to a load.

[0079] In some embodiments, the voltage source 403 is used to periodically apply a bias voltage (i.e. alternating voltage) to the perovskite solar cell at different voltage variation speeds in the bias mode, so as to suppress and alleviate the ion migration and the "fatigue" behavior of the perovskite solar cell during operation.

[0080] In the embodiments of the present disclosure, the bias voltage applied to the perovskite solar cell 20 by the voltage source 403 is similar to the bias voltage in the above-mentioned embodiments. For technical features not disclosed in detail in the embodiments of the present disclosure, please refer to the above-mentioned embodiments for understanding, which will not be described here again.

[0081] Figure 4 shows a schematic diagram of ion movement in the light-absorbing layer of a perovskite solar cell during operation. As shown in Figure 4(a), in the normal mode, under sunlight, the anions (such as I - , Br - or Cl - ) in the light-absorbing layer 203 migrate to the side of the electron transport layer 204 due to the built-in electric field, and accumulate at the interface between the light-absorbing layer 203 and the electron transport layer 204, and the cations (such as FA + , MA + or Cs + ) in the light-absorbing layer 203 migrate to the side of the hole transport layer 202, and accumulate at the interface between the light-absorbing layer 203 and the hole transport layer 202. Ion migration not only leads to the degradation of the efficiency of the perovskite solar cell device, but also is not conducive to the long-term operation of the device. As shown in Figure 4(b), in the "bias mode", since a bias voltage is applied to the perovskite solar cell 20, the accumulated anions and cations at the interface can be induced to redistribute and return to the original position in the light-absorbing layer 203, which is conducive to improving the performance and stability of the device and increasing the total power generation of the perovskite solar cell 20 in the normal mode.

[0082] Embodiments

[0083] Hereinafter, the embodiments of the present disclosure will be described. The embodiments described below are exemplary and are only used to explain the present disclosure, and cannot be understood as a limitation of the present disclosure. Unless otherwise stated, the reagents used are commercially available, and the equipment used is conventional equipment.

[0084] Example 1

[0085] The structure of the perovskite solar cell includes a first electrode, a hole transport layer, an interface modification layer, a light-absorbing layer, an electron transport layer and a second electrode stacked in order from bottom to top. The light-absorbing layer is a cesium formamidinium methylamine mixed perovskite (CsFAMA) with a thickness of about 500 nm; the first electrode is tin fluoride doped tin oxide (FTO for short) with a thickness of about 400 nm; the second electrode is a metal copper with a thickness of about 80 nm; the electron transport layer is C 60and a tin oxide compound, about 30 nm in thickness; a hole transport layer of nickel oxide, about 20 nm in thickness; and an interface modification layer of poly(9-vinylcarbazole).

[0086] First, the perovskite solar cell is aged, specifically, aged for 100 hours under continuous light irradiation of a solar simulator at 85°C and 1 sun intensity, so that the perovskite solar cell undergoes severe ion migration and accumulation.

[0087] Second, a bias voltage is applied to the perovskite solar cell: when the photovoltage of the perovskite solar cell is detected to be less than a preset photovoltage threshold (i.e. 0.5*Voc), a bias voltage is periodically applied to the perovskite solar cell, wherein the voltage range of the bias voltage is from -1*Voc to +2*Voc (wherein Voc represents the initial open-circuit voltage of the perovskite solar cell, i.e. the open-circuit voltage before aging), the scanning direction of the applied bias voltage is first reverse scanning (i.e. from +2*Voc to -1*Voc) and then forward scanning (i.e. from -1*Voc to +2*Voc), the voltage change speed of the bias voltage during reverse scanning is 100 mV / s, the voltage change speed of the bias voltage during forward scanning is 400 mV / s, the period of applying the bias voltage is 1 hour, and the total time length of the operation control of the perovskite solar cell is 12 hours.

[0088] Photovoltaic parameter test of perovskite solar cell

[0089] The perovskite solar cell in Example 1 is tested as follows in three device states of before aging, after aging, and after bias voltage application:

[0090] (1) Photoelectric conversion efficiency (PCE) test

[0091] The photoelectric conversion efficiency of the device is tested under standard test conditions using a solar simulator: total irradiance 100 mW / cm 2 , measured cell temperature 25°C, and spectral distribution AM1.5G. max The calculation formula is as follows: PCE = P in / P SC = J

[0092] , wherein P max is the maximum output power of the perovskite solar cell, P in is the incident light power, J SC is the short-circuit current density, V is the open-circuit voltage, and FF is the fill factor.

[0093] The open-circuit voltage and the short-circuit current density can be measured as follows:

[0094] The current density-voltage characteristic curve of the perovskite solar cell is tested, specifically, the test is performed using a Keithley 2400 digital source meter under a solar simulator AM1.5G (100 mW cm -2 ) and the current density-voltage characteristic curve of the perovskite solar cell is obtained, wherein the light intensity is calibrated using a standard silicon cell before the test.

[0095] The open-circuit voltage (V) of the perovskite solar cell is the voltage corresponding to the current density of 0 in the current density-voltage characteristic curve of the perovskite solar cell.

[0096] The short-circuit current density (J SC ) of the perovskite solar cell is the current density corresponding to the voltage of 0 in the current density-voltage characteristic curve of the perovskite solar cell.

[0097] (2) Recovery rate test Recovery rate = (PCE3-PCE2) / (PCE1-PCE2);

[0098] wherein PCE1 is the photoelectric conversion efficiency of the perovskite solar cell before aging, PCE2 is the photoelectric conversion efficiency of the perovskite solar cell after aging, and PCE3 is the photoelectric conversion efficiency of the perovskite solar cell after bias.

[0099] FIG. 5 shows the current density-voltage characteristic curves of the perovskite solar cell in Example 1 before aging, after aging, and after bias, from which the open-circuit voltage and the short-circuit current density of the perovskite solar cell before aging, after aging, and after bias can be obtained, and the specific values are shown in Table 1 below.

[0100] Comparative Example 1

[0101] Except that the step of applying bias is not performed, the rest is the same as Example 1.

[0102] Table 1 below shows the photovoltaic parameters of the perovskite solar cell in Example 1 and Comparative Example 1 before aging, after aging, and after bias.

[0103] Table 1:

[0104] The " / " in Table 1 indicates the absence.

[0105] As can be seen from Table 1, compared with Comparative Example 1 (without applying bias), in Example 1, after applying bias to the perovskite solar cell under the above conditions for 12 hours, the open-circuit voltage and the fill factor of the perovskite solar cell device can be basically restored to the state before aging, thereby improving the photoelectric conversion efficiency of the perovskite solar cell device, and the recovery rate of the perovskite solar cell device can reach 49.51%, effectively improving the stability and total power generation of the perovskite solar cell.

[0106] Example 2-8

[0107] The perovskite solar cell in Example 1 was biased in a similar manner as Example 1, except that the voltage range of the applied bias was different, as shown in Table 2 below.

[0108] Example 9

[0109] The perovskite solar cell in Example 1 was biased in a similar manner as Example 1, except that the voltage of the applied bias was constant, the time of the applied bias was 1 h, and the applied bias was not periodic, as shown in Table 2 below.

[0110] Table 2 below shows the photovoltaic parameters of the perovskite solar cells in Examples 2-9 before aging, after aging, and after biasing. For ease of comparison, the photovoltaic parameters of the perovskite solar cell in Example 1 before aging, after aging, and after biasing are also shown.

[0111] Table 2:

[0112] In Table 2, " / " means that there is no value; here V OC represents the initial open-circuit voltage of the perovskite cell, i.e., the open-circuit voltage before aging.

[0113] As can be seen from Table 2, when the voltage range of the applied bias is (-1 ~ 0) * V OC to (1 ~ 4) * V OC , especially -1 * V OC to 2 * V OC , the photoelectric conversion efficiency of the perovskite solar cell device is more significantly recovered (i.e., the recovery rate), effectively improving the stability and total power generation of the perovskite solar cell. For Example 3, when no positive bias is applied, the photoelectric conversion efficiency of the perovskite solar cell device after biasing is lower than that of the perovskite solar cell device after aging, which is not conducive to the recovery of the photoelectric conversion efficiency of the perovskite solar cell device. For Example 7, the perovskite solar cell device was damaged by breakdown after the bias was applied.

[0114] Example 10

[0115] The structure of the perovskite solar cell is stacked from bottom to top as follows: a first electrode, an electron transport layer, a light absorbing layer, a hole transport layer, a self-assembled modification layer, and a second electrode. The light absorbing layer is a formamidinium halide lead-based perovskite (FAPbI3) with a thickness of about 500 nm; the first electrode is fluorine-doped tin oxide (FTO) with a thickness of about 400 nm; the second electrode is a metal copper with a thickness of about 80 nm; the hole transport layer is 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) with a thickness of about 120 nm; and the electron transport layer is tin oxide with a thickness of about 20 nm.

[0116] First, the perovskite solar cell is aged, specifically, under the condition of 85°C and 1 sun intensity of a solar simulator, the perovskite solar cell is continuously irradiated for 100 hours, so that the perovskite solar cell has serious ion migration and accumulation.

[0117] Second, a bias voltage is applied to the perovskite solar cell: when the photovoltage of the perovskite solar cell is detected to be less than a preset photovoltage threshold (i.e. 0.5*Voc), a bias voltage is periodically applied to the perovskite solar cell, wherein the voltage range of the bias voltage is from -1*Voc to +2*Voc (herein Voc represents the initial open circuit voltage of the perovskite solar cell, i.e. the open circuit voltage before aging), the direction of the applied bias voltage is reverse scanning (i.e. from +2*Voc to -1*Voc), the voltage change speed of the bias voltage is 50 mV / s, the period of the applied bias voltage is 0.5 hours, and the total time length of the operation control of the perovskite solar cell is 12 hours.

[0118] Examples 11-15

[0119] Except that the voltage change speed of the applied bias voltage is different from that of Example 10, the rest is the same as that of Example 10, please refer to Table 3 below for details.

[0120] Examples 16 and 17

[0121] Except that the scanning direction of the applied bias voltage and the voltage change speed of the bias voltage are different from those of Example 10, the rest is the same as that of Example 10, please refer to Table 3 below for details.

[0122] Table 3 below shows the photovoltaic parameters of the perovskite solar cell in Examples 10-17 before aging, after aging, and after bias voltage.

[0123] Table 3:

[0124] As can be seen from Table 3, the photovoltaic conversion efficiency of the perovskite solar cell can be improved when the direction of the applied bias is forward scan and / or reverse scan. In addition, when the scan direction of the applied bias is reverse scan, the photovoltaic conversion efficiency recovery (i.e. recovery rate) of the perovskite solar cell device is more significant when the voltage variation speed of the bias is 200 mV / s to 400 mV / s.

[0125] Examples 18-22

[0126] Except that the period of applying bias is different from Example 1, the rest is the same as Example 1, please refer to Table 4 below for details.

[0127] Table 4 below shows the photovoltaic parameters of the perovskite solar cells in Examples 18-22 before aging, after aging, and after bias. For easy comparison, the photovoltaic parameters of the perovskite solar cell in Example 1 before aging, after aging, and after bias are also shown.

[0128] Table 4:

[0129] As can be seen from Table 4, when the interval time of applying bias is 0.5 hours to 4 hours, the photovoltaic conversion efficiency recovery (i.e. recovery rate) of the perovskite solar cell device is more significant, effectively improving the stability and total power generation of the perovskite solar cell.

[0130] Example 23

[0131] The structure of the perovskite solar cell includes a first electrode, a hole transport layer, an interface modification layer, a light absorbing layer, an electron transport layer, and a second electrode stacked in order from bottom to top. The light absorbing layer is a bromine-rich wide-bandgap perovskite (Cs 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3) with a thickness of about 400 nm; the first electrode is indium tin oxide (ITO) with a thickness of about 180 nm; the second electrode is metal copper with a thickness of about 80 nm; the electron transport layer is a C 60 and tin oxide complex with a thickness of about 30 nm; the hole transport layer is nickel oxide with a thickness of about 20 nm; and the interface modification layer is [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl] phosphonic acid.

[0132] The above perovskite solar cell is subjected to 600 hours of light / dark cycles after being continuously illuminated by a white light LED calibrated to one solar intensity for 12 hours, and then placed in the dark state for 12 hours as a cycle, to simulate real working conditions. The maximum output power of the perovskite solar cell is continuously tracked during this period.

[0133] In the above process of simulating real working conditions, when it is detected that the photovoltage of the perovskite solar cell is less than a preset photovoltage threshold (i.e. 0.5*Voc) (i.e. when the perovskite solar cell is in a dark state), a linear bias voltage is periodically applied to the perovskite solar cell, wherein the voltage range of the linear bias voltage is from -1*Voc to +2*Voc (wherein Voc represents the initial open circuit voltage of the perovskite solar cell, i.e. the open circuit voltage before aging), the scanning direction of the applied bias voltage is first reverse scanning (i.e. from +2*Voc to -1*Voc) and then forward scanning (i.e. from -1*Voc to +2*Voc), the voltage change speed of the bias voltage during reverse scanning is 100 mV / s, the voltage change speed of the bias voltage during forward scanning is 400 mV / s, the period of applying the bias voltage is different depending on the degree of decrease of the photoelectric conversion efficiency of the perovskite solar cell, and the total length of time for operating and controlling the perovskite solar cell is 12 hours. Specifically, in the case where the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.95*PCE0, the period of applying the bias voltage to the perovskite solar cell is 3 hours; in the case where the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.9*PCE0 and less than 0.95*PCE0, the period of applying the bias voltage to the perovskite solar cell is 2 hours; in the case where the photoelectric conversion efficiency of the perovskite solar cell is greater than or equal to 0.8*PCE0 and less than 0.9*PCE0, the period of applying the bias voltage to the perovskite solar cell is 1 hour; and in the case where the photoelectric conversion efficiency of the perovskite solar cell is less than 0.8*PCE0, the period of applying the bias voltage to the perovskite solar cell is 0.5 hour. PCE0 refers to the photoelectric conversion efficiency value under standard conditions, i.e. 25℃, 100 mW cm -2 The photoelectric conversion efficiency value measured when irradiated with AM1.5G spectrum light at an irradiation intensity.

[0134] Example 24

[0135] Except that the time interval for applying the bias voltage is constant at 2 hours, the rest is the same as Example 23.

[0136] Comparative Example 2

[0137] Except that the step of not applying the bias voltage, the rest is the same as Example 23.

[0138] Figure 6 shows a comparison of the steady-state power output of the perovskite solar cells in Example 23, Example 24 and Comparative Example 2 under simulated real-world conditions. The perovskite solar cells in Example 23, Example 24 and Comparative Example 2 have the same initial photoelectric conversion efficiency. As can be seen from Figure 6, after 600 hours of light / dark cycle testing, the normalized output power of the perovskite solar cell in Comparative Example 2 decreased significantly and exhibited a clear "fatigue" behavior; the normalized output power of the perovskite solar cell in Example 24 decreased and exhibited a "fatigue" behavior to a lesser extent than Comparative Example 2; and the normalized output power of the perovskite solar cell in Example 23 decreased relatively slowly. Thus, the control method of the present disclosure can effectively improve the stability and total power generation of perovskite solar cell devices.

[0139] The retention rate of the perovskite solar cell devices in Example 23, 24 and Comparative Example 2 can be calculated as follows:

[0140] Retention rate = PCE 测试后 / PCE 测试前 .

[0141] Table 5 below shows the photovoltaic parameters of the perovskite solar cells in Example 23, 24 and Comparative Example 2 before and after testing.

[0142] Table 5:

[0143] As can be seen from Table 5, compared to Comparative Example 2 (no bias applied), the photoelectric conversion efficiency of the perovskite solar cell devices is improved by applying a bias to the perovskite solar cells in Examples 23 and 24, effectively improving the stability and total power generation of the perovskite solar cells. Compared to a fixed bias application period, applying a bias at different periods according to the degree of decrease in the photoelectric conversion efficiency of the perovskite solar cells can further improve the stability and total power generation of the perovskite solar cells.

[0144] It should be noted that the present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration and playing the same role and effect within the scope of the technical solutions of the present disclosure are included in the technical scope of the present disclosure. Furthermore, within the scope of the main idea of the present disclosure, various modifications that can be thought of by those skilled in the art, or other modes of implementation constructed by combining some of the components of the embodiments are also included in the scope of the present disclosure.

Claims

1. A method for operating control of a perovskite solar cell, the method comprising: detecting a photovoltage of the perovskite solar cell; and applying a bias voltage to the perovskite solar cell when the photovoltage is less than a preset photovoltage threshold. x is -1 to 0, and y is 2 to 4. The bias voltage applied to the perovskite solar cell is an alternating voltage.

2. The method of claim 1, wherein, The voltage range of the bias voltage is x*V OC to y*V OC , wherein x is -1-0, y is 1-4; V OC is the initial open circuit voltage of the perovskite solar cell.

3. The method of claim 2, wherein, In the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied in a forward scan and / or a reverse scan.

4. The method of any one of claims 1-3, wherein, The voltage range of the bias voltage is -1*V OC to 2*V OC , V OC is the initial open circuit voltage of the perovskite solar cell.

5. The method of any one of claims 1-4, wherein, In the step of applying a bias voltage to the perovskite solar cell, the bias voltage is applied at a voltage change rate of 50 mV / s to 1500 mV / s.

6. The method of any one of claims 1-5, wherein, In the case of applying the bias voltage in the reverse scan or the forward scan, the bias voltage is applied at a voltage change rate of 200 mV / s to 400 mV / s.

7. The method of claim 6, wherein, In the case of applying the bias voltage in the reverse scan and the forward scan, the voltage change rate of the bias voltage in the reverse scan is 50 mV / s to 500 mV / s, and the voltage change rate of the bias voltage in the forward scan is 300 mV / s to 1000 mV / s.

8. The method of claim 7, wherein, The step of applying a bias voltage to the perovskite solar cell comprises periodically applying the bias voltage to the perovskite solar cell. The period of applying a bias voltage to the perovskite solar cell is 1 minute to 12 hours.

9. The method of any one of claims 1-8, wherein, The period of applying a bias voltage to the perovskite solar cell is 0.5 hours to 4 hours.

10. The method of claim 9, wherein, In the case of a photoelectric conversion efficiency of the perovskite solar cell being greater than or equal to 0.95*PCE0, the period of applying a bias voltage to the perovskite solar cell is 3 hours to 12 hours.

11. The method of claim 10, wherein, In the case of a photoelectric conversion efficiency of the perovskite solar cell being greater than or equal to 0.9*PCE0 and less than 0.95*PCE0, the period of applying a bias voltage to the perovskite solar cell is 2 hours to 4 hours.

12. The method of claim 10 or 11, wherein, In the case of a photoelectric conversion efficiency of the perovskite solar cell being greater than or equal to 0.8*PCE0 and less than 0.9*PCE0, the period of applying a bias voltage to the perovskite solar cell is 1 hour to 2 hours. In the case of a photoelectric conversion efficiency of the perovskite solar cell being less than 0.8*PCE0, the period of applying a bias voltage to the perovskite solar cell is 0.5 hours to 1 hour. The method for operating control of a perovskite solar cell is applied to a perovskite solar cell with a photoelectric conversion efficiency less than 0.95*PCE0. 15.A system for operating control of a perovskite solar cell, the system comprising: a detection unit configured to detect a photovoltage of the perovskite solar cell; a voltage source; and a control module connected to the voltage source and configured to control the voltage source to apply a bias voltage to the perovskite solar cell when the photovoltage of the perovskite solar cell is detected to be less than a preset photovoltage threshold. said PCE0 is the photoelectric conversion efficiency of said perovskite solar cell measured at 25 °C, 100 mW cm -2 said PCE0 is the photoelectric conversion efficiency of said perovskite solar cell measured at 25 °C, 100 mW cm 13. The method of any one of claims 1-12, wherein, ​ said PCE0 is the photoelectric conversion efficiency of said perovskite solar cell measured at 25 °C, 100 mW cm -2 said PCE0 is the photoelectric conversion efficiency of said perovskite solar cell measured at 25 °C, 100 mW cm 14. The method of any one of claims 1-13, wherein, The preset photovoltage threshold is 0-0.6*V OC ;V OC Is the initial open circuit voltage of the perovskite solar cell. ​ ​ ​ ​

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