Characteristics of a-SiC:H/a-SiGe:H hetero-junction thin film solar cells with and without a-Si:H buffer layer at the p/i interface

摘要

This article shows the characteristics on a-SiGe:H based solar cells with various structures. Based on these results, we proposed the a-SiC:H/a-SiGe:H hetero-junction thin film solar cells with a-Si:H buffer layer at the p/i interface to improve the performance of pin-type a-SiGe:H based solar cell. All films of amorphous materials were deposited by 13.56 MHz PECVD method. The effects of deposited parameters on the characteristics of a-SiC:H and a-SiGe:H films have been investigated by ultraviolet-visible-near infrared (UV-VIS-NIR) spectrophotometer. The various values of V_(oc),J_(sc), FF and η were measured under 100 mW/cm~2 (AM 1.5) solar simulator irradiation. In the proposed structure, we achieved a higher conversion efficiency than general a-SiGe:H solar cell and a-SiC:H/a-SiGe:H hetero-junction thin film solar cells without a-Si:H buffer layer at the p/i interface. Based on results obtained from this study, we discuss the roles of a-Si:H buffer layer in a-SiC:H/a-SiGe:H hetero-junction thin film solar cells.