Characterization of co-sputtered MgxZn1-xO thin films and their application in CdTe solar cells

In this paper,MgxZn1-xO (MZO) films with x from 0 to 0.25 were prepared by radio frequency (RF) magnetron co-sputtering, and the structure, surface morphology, optical and electronic properties of MZO films were investigated. With the increase of Mg content, the crystallinity of MZO films became worse with the appearance of grain agglomeration, and the optical energy band gap (E-g) linearly changed from 3.228 eV to 3.824 eV. The MZO films with different Mg content were used as the window layer for CdTe solar cells with or without CdS layer. The efficiency of MZO/CdTe devices is much lower than MZO/CdS/CdTe devices. Incorporating a buffer layer CdS into CdTe solar cells can significantly improve the devices efficiency, and the devices still maintain a high spectral response in the short wavelength region.