Study On Synthesis Process And Photoelectric Properties Of Low Dimensional CdS Materials In Hydro-and Solvothermal Methods

CdS(2.42 eV)is a semiconductor material with excellent electron transport capability and has been widely used as an ETL in CdTe and CuInGaSe solar cells.Moreover,CdS is used as a new type of electron transporting material in PSCs because of its good electron conductivity,good energy band matching with perovskite materials,simple preparation and low cost.The new CdS thin film material of ETL can effectively prevent electrons and holes from recombining in PSCs,and enhance current without sacrificing other parameters(such as Voc,FF,etc.),thereby,achieving excellent photovoltaic performance.Studies have shown that when CdS is used as the ETL of PSCs,the stability of the battery is significantly improved.Therefore,the preparation of a uniform,dense CdS film is of great significance for improving the photoelectric conversion eff-iciency and stability of PSCs.For synthesizing CdS nanofilms,hydro-solvothermal methods have attracted widely attention from many researchers because of their mild conditions,simple preparation,large-scale production,and high preparation rate.In this paper,various morphologies of CdS nanocrystals and films were prepared by these methods.The effects on product morphologies,microstructure and light absorption properties were analyzed.Additionally,the possible mechanisms were analyzed.The electrical properties of the film were analyzed by photocurrent density.Finally,the effect of thin layer CdS on the optical properties of the perovskite solar cell device structural unit was initially simulated.The main conclusions were as follows:(1)The dendritic and hexagonal CdS nanocrystals were synthesized via a hydrothermal method.In addition,CdS nanorods were synthesized via a solvothermal method.(2)Different morphological CdS films were synthesized by different reaction systems:Hexagonal cone-shaped CdS nanofilms were synthesized by hydrothermal method,and the films were dense and uniform.And the substrate and solvents are important factors influencing the morphology of the film;(3)Spectrogram analysis of the product showed that the PL peaks of CdS film showed a significant red shift,while the UV-vis DRS of the powders and films of different morphologies also appeared the difference.(4)After adding a thin CdS layer to the surface of the ETL in PSCs device,the optical properties of the PSCs had major changes.