Research On Key Materials For CZTSe Thin Film Solar Cell Application

Thin film solar cell based on CZTSe (Cu2ZnSnSe4) materials is considered as a promising candidate for very large scale application in the future due to the excellent material properties and low cost.In this thesis, the performance of CZTSe thin film solar cell was numerical simulated using SCAPS-1D software. The influences of parameters such as the band gap of CZTSe, the thickness of CZTSe absorber layer and CdS buffer layer, the working temperature and resistance on the performance of CZTSe thin film solar cell were studied.IMO (In203:Mo) thin films were prepared by pulsed DC magnetron sputtering method. The impacts of substrate temperature on the properties of IMO were investigated. The results demonstrated that all the IMO thin films exhibited bixbyite cubic structure of the In2O3. The mobility showed an increasing trend in general and the maximum mobility of53.9cm2V-1s-1at250℃was obtained. The IMO films prepared at higher substrate temperature showed better optical transmission in the visible range. Their band gaps were calculated to be larger than3.5eV, which is suitable as TCO layer for solar cell.CZTSe thin films were fabricated by selenization of sputtered metallic precursors. The CuZnSn precursors were prepared by co-sputtering and then selenized in a tube furnace under different pressure(1～4mbar). The XRD results indicated the presence of CZTSe while the EDS analysis showed that the compositions were near stoiehiometrie. However, the homogeneity of the grain is poor. The CZTSe thin films showed P-type conductivity with resistivity in the order of10-2Ω·cm and carrier concentration of10～10cm-3. After KCN etching, the resistivity increased and the carrier concentration decreased. The optical band gap obtained from the CZTSe thin films after KCN treatment was about0.92eV.