Preparation And Photovoltaic Properties Of Indium Antimony Modified Silver Sulfide Antimony Composite Films By Spray Pyrolysis

AgSbS₂ is a kind of inorganic chalcogenide metal ternary compound material with a series of advantages,such as high light absorption coefficient,simple composition and easy preparation,low cost and green environmental protection,etc.It is a promising photovoltaic material.However,at present,the device efficiency of AgSbS₂thin film solar cells is not high,and the preparation process is not mature enough,and the thin film preparation is prone to appear heterophase,conduction band offset and other problems.In this thesis,a kind of AgSbS₂composite film with In and Sb added separately was prepared on CdS by spray pyrolysis as an absorption layer,and the conversion process occurred in the idle time of spray cycle replacement,making the two films form a unified film,solving the problem of interaction between In and Sb elements when they were added and modified at the same time,and playing their respective modification roles as far as possible.The energy level structure is optimized by introducing the conduction band grading by adding a single element modified absorption film on the back.The research work mainly includes two parts:（1）In the case that the total spraying period is four cycles,the effects of different spraying cycle combinations on the film and its devices are studied.There are five spray cycle combinations:4T（In）,3T（In）+1T（Sb）,2T（In）+2T（Sb）,1T（In）+3T（Sb）and 4T（Sb）.The study found that the appropriate combination of spraying cycles,namely thickness combination,is conducive to the film phase formation,improves the film’s light absorption ability,and makes full use of the comprehensive modification and optimization of In and Sb.The Jsc and Voc of the device have been improved by different degrees,and the efficiency has been greatly improved.At the same time,the effect of selenidation time on the performance of thin films and devices was studied.When the selenidation time was too long,the morphology of thin films would drop sharply,resulting in a significant reduction in device efficiency.（2）Under the condition of appropriate spray cycle combination,the effects of different spray sequence combinations on films and devices were studied.There are three spray sequence combinations:2T（In）+2T（Sb）,1T（In）+2T（Sb）+1T（In）and 2T（Sb）+2T（In）.The results show that AgSb_1.25（S,Se）_2.75thin film has small grains,loose structure and poor morphology.When it is directly contacted with CdS buffer layer,it is easy to have poor adhesion,which affects carrier transport.When AgIn_0.5Sb（S,Se）₂is directly contacted with CdS buffer layer,it can not only avoid this problem,but also optimize the energy level structure and promote carrier transport.Proper spray sequence combination can optimize the interface,improve the light absorption characteristics of the film,optimize the energy band structure,and promote carrier transport.Comprehensive and the above work,this thesis prepared AgSbS₂composite film with In and Sb as the absorption layer,studied the spraying cycle combination and spraying sequence combination for the influence of thin film and its device,compared with AgSbS₂standard,Jsc and Voc get different range,while the device FF also increased to 50%,to ensure the high efficiency of the device,the best device efficiency reached 3.57%.