Optimization Of Sb₂S₃ Thin Films Prepared By Hydrothermal Method And Application Of Solar Cells

Antimony sulfide(Sb₂S₃)is a cheap,non-toxic and abundant photovoltaic material with excellent photoelectric characteristics such as high absorption coefficient and suitable band gap.In the 1990s,Sb₂S₃ was applied to solar cells as a photovoltaic material.With the continuous exploration of this field by researchers,Sb₂S₃ solar cells ushered in their golden period of rapid development in the past decade.So far,Sb₂S₃ thin film solar cells can achieve the highest photoelectric conversion efficiency of 7.5%,which has attracted more and more attention in the photovoltaic field.However,with the development of recent years,Sb₂S₃ thin film solar cells have been exposed to the poor quality of the absorbent layer,many defects,serious carrier recombination and other problems.In view of the current situation and existing problems of Sb₂S₃thin film solar cells,this topic is based on the hydrothermal method to prepare Sb₂S₃ thin film,the specific research work is as follows:(1)Three kinds of electron transport layers,SnO₂,TiO₂ and CdS,were prepared,and the J-V electrical properties of Sb₂S₃ solar cells were tested.The results show that the efficiency of the two devices based on SnO₂/Sb₂S₃ and TiO₂/Sb₂S₃ structures is low,and the photoelectric conversion efficiency of the devices based on CdS/Sb₂S₃ structure is the highest,which can reach1.92%.This indicates that the performance improvement of Sb₂S₃ thin film solar cells not only depends on the improvement of the quality of the absorbent layer.Coordination among the functional layers is also important for improving battery performance.Finally,the preparation method of CdS electron transport layer was optimized to determine the best reaction time.(2)The morphology of Sb₂S₃ films prepared under different experimental conditions was analyzed,and the best conditions for preparing Sb₂S₃ films by hydrothermal method were determined in combination with the performance test of batteries.The results show that the increase of annealing temperature can promote the crystallinity of Sb₂S₃ films.Sb₂S₃ films with large grains and good crystallinity are obtained at 360?.The growth orientation of Sb₂S₃ thin films was regulated by annealing rate and hydrothermal temperature.The optimal growth of Sb₂S₃thin films was obtained at annealing rate of 10?/min and hydrothermal temperature of 140?.Subsequently,J-V and other detailed electrical performance tests were carried out on the device.The results showed that the improved crystallinity and the longitudinal selective growth of the film contributed to the improvement of the battery performance.Finally,through further optimization of Sb₂S₃ film thickness,494 nm thick film was prepared under 6 h hydrothermal time,and Sb₂S₃solar cells with conversion efficiency of 4.75%were obtained.(3)In order to further improve the photoelectric conversion efficiency of the cell,the influence of Al₂O₃ passivation on the performance of Sb₂S₃ solar cells was investigated.CdS/Sb₂S₃interface was passivated by Al₂O₃,and the performance of Sb₂S₃ solar cells was compared and analyzed.The results show that Al₂O₃ passivation layer can effectively improve the interface quality of the battery,block the reverse transfer of electrons at the CdS/Sb₂S₃ interface,and inhibit the recombination of carriers.The maximum photoelectric conversion efficiency of 5.90%was obtained by passivation of Al₂O₃.In this paper,a simple and low-cost way to prepare Sb₂S₃ thin films is introduced,and it provides technical support for the further development of Sb₂S₃ thin film solar cells.