Research Of AgSbS₂ Thin Film Prepared By In Situ Spray Pyrolysis And Photovoltaic Performance

As a new inorganic photovoltaic material,silver sulfur-antimony(Ag Sb S₂)is considered as a promising photovoltaic absorber material due to its suitable band gap,large absorption coefficient and environmental friendliness.In recent years,some progress has been achieved in the preparation process and device structure of Ag Sb S₂thin-film solar cells.However,the photovoltaic performance of the devices is far from the expectation at present due to the poor crystallinity of the films and the undesirable alignment of the energy band structure.Elemental doping(including elemental addition and elemental substitution)and component conditioning are common methods to improve material properties and enhance the crystallinity of thin films.In this work,in situ spray pyrolysis was used to prepare thin films.The properties and the crystallinity have been improved by indium doping and different Ag/Sb adjustment,and their effects on the physical phase structure was investigated,as well as morphological structure,energy band structure of the films and photovoltaic performance of the devices.The study included the following two parts.(1)The photovoltaic performance of the device was improved by adding indium to the Ag-Sb-S system followed by a selenization process.By optimizing the indium content,the photovoltaic conversion efficiency of the device was successfully increased from 0.74%to 1.98%.And the Ag In_xSb S₂(Se)device had good stability.It was shown that the addition of In was beneficial to the nucleation process of the film,which improved the crystallinity of the film.The film became more compact and the morphological uniformity was improved.In addition,the addition of In effectively increased the carrier concentration of the film and significantly enhanced the light absorption,so that the device exhibited a higher short-circuit current density.(2)The In-doped films were further investigated by adjusting different Ag/Sb ratios.By optimizing the Ag/Sb ratio,the photovoltaic conversion efficiency of the devices was increased by three times.It was shown that the phase purity and the crystallinity of the films was significantly improved,and the films were more compact after appropriately increasing the Sb content in the films.Both the light absorption and carrier transport of the film were effectively enhanced.Meanwhile,the conduction band offset between the absorber layer and buffer layer was significantly reduced,the energy band alignment structure was optimized,and the carrier recombination at the interface was reduced.In summary,this work prepared thin films by in situ spray pyrolysis and effectively enhanced the device performance by indium doping and different Ag/Sb adjustments,and was of reference value for further research on Ag Sb S₂ thin-film solar cells.