Passivation of a-Si:H-based structures in KCN and HCN solutions and its application on p-i-n solar cell

Abstract

Dominant aim of the contribution is focused on investigation of very thin SiO 2 /a-Si:H interface properties. After PECVD deposition, surface of a-Si:H is not covered by reproducibly defined insulating layer. Therefore, three basic types of oxygen plasma sources were used for treatments of a-Si:H surfaces. Electrically well defined SiO 2 very thin film layers are formed by (i) inductively coupled plasma in connection with its applying at plasma anodic oxidation, (ii) RF plasma as the source of positive oxygen ions for plasma immersion ion implantation process, and (iii) dielectric barrier discharge ignited at high pressures. In addition, chemical oxidation of a-Si:H surface was performed in boiling azeotropic HNO 3 solutions. Electrical properties of SiO 2 / semiconductor interface of both a-Si:H-and Si-based structures were improved by treatments in KCN and/or HCN solutions. Positive passivation influence of last mentioned solutions is presented on p-i-n a-Si-H solar cell parameters.