The research of post-treatment on Cd1-xMgxTe thin films and CdTe solar cells

Abstract

As for it higher band gap, Cd1-xMgxTe (CMT) material has been taken into consideration to improve the open-circuit voltage of CdTe solar cells as an electron reflector layer. An essential step in the development of this new interlayer is the passivation process. X-ray Diffraction (XRD) and scanning electron microscope (SEM) results give us the suitable annealing temperature range of CMT thin films from 350°C to 400°C, and suggest that the annealing process is beneficial to grain growth and recrystallization. The concentration of CdCl2 solution has an influence on the crystallinity of the thin films and coating method would contribute to electrical performance of the devices. The CMT/CdTe cells which underwent the two-step annealing procedure at high purity nitrogen atmosphere showed the significant improvements in device performance. Furthermore, the CdTe solar cells with the CdTe cap layer and Te/Cu back contacts also demonstrated higher performance.