Theoretical Prediction And Fabrication Of Perovskite Solar Cells Based On Different Perovskite Structures

At present,PCE of perovskite solar cells（Perovskite Solar Cells,PSCs）has exceeded 26%,making it one of the most promising photovoltaic technologies in the third generation of thin film solar cells.With the progress of large-scale commercialization,it is particularly important to develop solar cells with different device structures and new perovskite materials.Although different perovskite structures and device types have been continuously explored in recent years,disruptive device structures and technologies have not yet been produced.Therefore,this paper firstly carried out the construction of a new type of perovskite solar cell based on the hollow structure;at the same time,a new type of perovskite solar cell with an intermediate energy band structure was theoretically designed and predicted.The main research contents are as follows:（1）Lead-free perovskite solar cells based on hollow structures.A hollow structure with randomly distributed Schottky defects is formed by introducing ethylenediamine（EDA）into the FA_0.75MA_0.25Sn I₃ perovskite structure.This special perovskite structure has achieved a good synergistic effect in reducing the defect state density inside the film and preventing Sn²⁺oxidation,and at the same time constructed a planar p-i-n reflector of ITO/PEDOT:PSS/perovskite film/C60/BCP/Ag.Tin-based perovskite solar cells’photovoltaic performance and stability are considerably enhanced by EDA.Through the optimization of the preparation parameters of each layer,a device efficiency of 11.46%was finally achieved,in which V_oc was 0.67 V,J_sc was 23.5 m A cm^-2,and FF was 0.728,and the hysteresis effect was small,indicating that the device had excellent photoelectric properties and slowed down the charge accumulation on the interface.And exhibited good stability,after 400 h storage in N₂ atmosphere,still retain more than 90%of the initial efficiency,which provides a way to prepare efficient and stable tin-based PSCs.（2）Taking A’[Pb₂X₆]as the research object,we theoretically predicted the optoelectronic performance of a perovskite solar cell with a novel intermediate energy band.Where A’is an organic molecule:N,N’-dimethylpyrazine（dmpz）,N-hydrogen-N’-methylpyrazine（Hmpz）or N-hydrogen-N’-ethylpyrazine（Hepz）,etc.,X is a halide:iodine（I）or bromine（Br）,etc,this novel perovskite structure facilitates charge separation at the organic-inorganic interface to achieve lattice doping,and there is an intermediate band with less half-occupancy and dispersion,thereby constructing intermediate-band solar cells.Using the classic model of semiconductor carrier diffusion to explore the variation law of the theoretical limit photoelectric conversion efficiency of this halide perovskite-based intermediate zone solar cell under different limiting factors,the results show that the non-radiative recombination loss and the overheating of the cell above the ambient temperature will lead to the reduction of the efficiency of the perovskite-type intermediate zone solar cell working under the full concentration or a standard sunlight intensity.This work is crucial for advancing the creation and use of intermediate solar cells because it offers a strong theoretical foundation for the experiment.