Preparation And Research Of Cu2znsns4film By Solution Route

Cu2ZnSnS4is a solar absorbing layer material with high performance, it has ahigh light absorption coefficient (greater than104cm-1), and the band gap isapproximately1.05-1.5eV, which matches the optimal band gap of the solar cell(1.4-1.50eV). Besides, each components of Cu2ZnSnS4is abundant in earth’s crust,and it had attracted worldwide attention. The paper is mainly aiming to designreasonable experimental route, optimize experimental parameters, and use thenon-vacuum process route to prepare Cu2ZnSn(S,Se)4materials from the cost controland environmentally friendly two angles. Then the prepared materials were analyzedand characterized. This will lay the foundation for Cu2ZnSnS4thin film solar celldevice development and application. The contents of this paper can be divided intothe following three parts:(1) Cu2ZnSnS4nanocrystals prepared by single-source precursor pyrolysisA modified solvothermal method, ie single-source precursor pyrolysis wasdesign to prepare Cu2ZnSnS4nanocrystals. The influence of reaction temperature,reaction time and other experimental factors on the phase and the size of the preparedCu2ZnSnS4was investigated. Then the formation mechanism of the nanocrystals wasdiscussed.(2) Cu2ZnSn(S,Se)4thin films prepared by ethanol-based homogeneous solutionmethodEnvironment-friendly solvent ethanol was used as solvent, inorganic saltsCuCl2·2H2O, ZnCl2, SnCl2·2H2O and thioacetamide (TAA) were used as rawmaterials. The Cu2ZnSnS4precursor films were prepared by dip-coating method.Then the prepared [CuZnSn(TAA)n]m+precursor films were annealed under sulfide orselenide vapor to obtain Cu2ZnSnS4or Cu2ZnSn(S,Se)4films with thickness up to1.32μm.(3) Cu2ZnSn(S,Se)4thin films prepared by isopropanol-based homogeneoussolution methodEnvironment-friendly solvent isopropanol was used as solvent for the first timeto prepare Cu2ZnSnS4precursor films by dip-coating method using the homemadedip-coating equipment. Then the prepared [CuZnSn(TAA)n]m+precursor films wereannealed under sulfide or selenide vapor to obtain Cu2ZnSnS4or Cu2ZnSn(S,Se)4 films. The thickness, phase and particle size of Cu2ZnSnS4or Cu2ZnSn (S,Se)4thinfilms were control by changing the layers, the annealing temperature and annealingtime. When the layers was up to16and the annealing temperature reached500oC, thethickness of film reached1.25μm, and the individual grains could grow to around800nm.