Growth And Properties Of Cs₃Bi₂I₉/MoS₂ Heterojunction By Chemical Vapor Transport

Ultrathin perovskite has attracted extensive research due to its atomic size thickness,long carrier lifetime and strong light absorption,but its relatively high photogenerated carrier recombination rate limits its application in optoelectronic devices.The two-dimensional Mo S₂crystal has high carrier mobility and on/off ratio.At the same time,inspired by the two-dimensional material heterojunction（HS）,the construction of perovskite/two-dimensional material heterojunction can effectively improve the carrier mobility and light absorption,promote the separation of photogenerated carriers,etc.,thereby significantly improving the performance of photodetectors.The perovskite/two-dimensional material heterojunction is a way to solve this problem.In this paper,the heterostructure of Cs₃Bi₂I₉/Mo S₂ was synthesized by CVT method,and its structure and properties were characterized.The main research contents are as follows:1.Inorganic perovskite Cs₃Bi₂I₉ and two-dimensional material Mo S₂ were synthesized by CVT method.By adjusting a series of experimental conditions,such as the ratio of reactants,reaction time,type of transport agent,temperature,etc.,the target product with regular morphology and high quality was synthesized,and through a series of characterization,it was shown that the synthesized material has high quality.2.The synthesis process of Cs₃Bi₂I₉/Mo S₂ heterojunction was explored,and the reaction conditions were optimized.The heterojunction of inorganic perovskite Cs₃Bi₂I₉ and two-dimensional material Mo S₂ was synthesized on mica by one-step method.It is found that the photoluminescence intensity of multilayer Mo S₂ will be improved after the synthesis of heterojunction.3.The structure and physical properties of Cs₃Bi₂I₉/Mo S₂ heterojunction were characterized.Raman,PL,XPS,AFM and other characterization methods are used to prove that the synthesized heterojunction has good crystallinity.At the same time,the femtosecond pump measurement is used to study the photodynamic process of the heterojunction and reveal the energy transfer process in the heterojunction.In this work,Cs₃Bi₂I₉/Mo S₂ heterojunction was successfully synthesized by CVT method,which provides a new method for the formation of heterojunction between inorganic perovskite and TMDCs,and also provides a basis for the preparation of heterojunction devices.