Preparation And Photoelectrochemical Properties Of CdZnTe Films By Close-spaced Sublimation Method

Energy is a key issue affecting the development of human society.As an efficient,environmentally friendly and non-polluting energy source,hydrogen has huge advantages.By selecting suitable photoelectrode materials,photoelectrochemical（PEC）water splitting to hydrogen production can be realized using renewable solar energy,which is a research hotspot at home and abroad.Cadmium zinc telluride（CdZnTe）is a group II-VI direct bandgap compound semiconductor with excellent performance.Due to its ideal optical bandgap,good charge transport properties,low leakage current,low noise and other properties,CdZnTe can be widely used in high energy radiation detectors,solar cells,photoelectrochemical（PEC）water splitting for hydrogen production and other fields.In this thesis,the preparation of CdZnTe thin films and CdZnTe:In thin films by near-space sublimation method and their application in photoelectrochemical（PEC）water splitting are studied.The main contents and achievements of the thesis are as follows:（1）The effects of different deposition times on the morphology,structure,morphology,optical properties and electrochemical properties of CdZnTe films and CdZnTe:In films were studied.Mott-Schottky test and PEC water splitting test show that the conductivity type of CdZnTe film is p-type,and the conductivity type of CdZnTe:In film is n-type.With the increase of deposition time,the grain size and band gap of CdZnTe film and CdZnTe:In film increases,and the photocurrent density increases first and then decreases.Doping In can improve the optoelectronic properties of CdZnTe films.The highest photocurrent density of the films deposited for 4 hours can reach 1.83 m A/cm² and 3.66 m A/cm²,respectively.（2）The effects of different annealing temperatures on the water splitting performance of CdZnTe films and CdZnTe:In films were studied.The results showed that the annealing treatment improved the stability of CdZnTe films and CdZnTe:In films,and the optimal annealing temperature was 450℃.After annealing,the photocurrent density of CdZnTe thin film and CdZnTe:In thin film can reach the highest 3.33 m A/cm² and 4.12 m A/cm²,respectively.（3）The FTO/CdZnTe:In/TiO₂/Pt photoanode structure was successfully synthesized with CdZnTe:In film as light absorption layer.The optimal thickness of Pt catalytic layer and TiO₂ protective layer were both 3 nm.The photoelectrode structure prepared on this basis has large photocurrent density and good photocurrent stability,and the maximum photocurrent density was about 8.4 m A/cm².