Abstract
In this study, we investigated the thermal effect on the electronic properties of the commercial Cu(In,Ga)(Se,S)2 (CIGSeS)-based solar cell by using a nondestructive method, hard X-ray photoemission spectroscopy (HAXPES). The samples were individually air annealed to 60 °C, 120 °C and 180 °C in a quartz tube for 48 hrs. The ZnO layer was etched to form a gradient thickness by HCl (0.1%) for depth information. The quantitative analysis of the HAXPES results shows that all of the elements in the surface region of the CIGSeS absorber layer were upwardly diffused and, for CdS buffer layer, the sulfur atoms exhibit an upward diffusion after thermal treatment. The thermal annealing treatment accelerates the disappearance of the ordered defect compounds (ODC) domains and the elemental interdiffusion at the ZnO/CdS/CIGSeS interfaces, further leading to a decrease of the short current density.
