Preparation And Performance Study Of Sb₂S₃ Thin Film Solar Cells By Chemical Bath Deposition

Solar energy is a kind of renewable clean energy,while photovoltaic technology that can convert solar energy into electric energy has attracted wide attention.Among many photovoltaic materials,metal chalcogenides possess excellent photoelectric properties.In particular,Sb2S3,as a novel light absorbing material has caught more and more interests for many advantages,such as simple and abundant components,various and stable preparation methods,appropriate optical band gap and large light absorption coefficient.Chemical bath deposition(CBD)method is widely used in the preparation of Sb2S3 solar cells because of its simple operation equipment,controllable reaction process and favorable large-scale production.However,the traditional CBD method for Sb2S3 thin film is limited by lower utilization rate of raw materials,more introduced impurities,and the power conversion efficiency(PCE)of the Sb2S3 solar cell prepared by CBD method is low as well.This paper could be able to sort into two aspects.On the one hand,we introduced the complex agent ethylenediaminetetraacetic acid(EDTA)into the reaction system to improve the traditional CBD method,since EDTA could control the growth of Sb2S3 film through forming a complex with antimony ion.Furthermore,the deposition conditions and pre-annealing treatment are also studied to reduce the formation of impurity phase and improve the film quality.On the other hand,we applied sodium thiosulfate,thioacetamide,thiourea,selenium dioxide,and so on for the post-treatment of Sb2S3 film prepared by CBD method to further optimize the film morphology and obtain high efficient solar cell.In the first chapter,the development history,principle,performance parameters and classification of solar cells are briefly introduced,and then my graduate research topics and methods in my graduate stage are proposed.In the second chapter,the properties of antimony sulfide and the development of Sb2S3 thin film solar cells are reviewed,and the preparation methods of Sb2S3 film and the characterization technology of the thin films as well as solar cells are introduced.In the third chapter,the preparation of Sb2S3 film by CBD with EDTA as complex agent is investigated in detail.By adjusting the reaction conditions such reaction temperature,solvent,sample bottle,dosage of complex agent and pre-annealing treatment,it turns out that the quality of Sb2S3 film deposited by improved CBD method is enhanced.In addition,we assembled the solar cell with structure of FTO/compact TiO2/Sb2S3/Spiro-OMeTAD/Au,and the PCE of solar cell increased from 3.55%to 5.56%since the introduction of the complex agent.In the fourth chapter,the post treatment of Sb2S3 film prepared by improved CBD method using three sulfur sources(sodium thiosulfate,thioacetamide,thiourea)and selenium dioxide was studied systematically.The results show that thioacetamide perform best for post-treatment among the three sulfur sources,reducing the pin holes and improving the crystallinity of the film.Particularly,a small amount of selenium can be doped into the Sb2S3 film to form Sb2(S1-xSex)3 when selenium dioxide was applied for post treatment.With the optimal concentration of selenium dioxide post-treatment,the planar heterojunction solar cells obtained PCE of 5.72%.The fifth chapter is the summary of my work during graduate period,and it reflects on the problems existing in the research and prospects for future research.