Si thin film solar cells using SiH2Cl2 by rf plasma-enhanced chemical vapor deposition

Abstract

The fabrication of p–i–n Si thin film solar cells using a SiH2Cl2–H2 mixture by rf plasma-enhanced chemical vapor deposition is presented. A novel p-type nanocrystalline Si:H:Cl film was synthesized from H2-diluted SiH2Cl2 and SiCl4 with high conductivity and low optical absorption in the visible and near-infrared regions. The Si:H:Cl films showed a high photoconductivity of order of >10−6S/cm under 100mW/cm2 white light exposure. The efficiency of 6.2% has been achieved in the p–i–n solar cells fabricated from a SiH2Cl2–H2 mixture at Ts of 340°C for the first time despite a use of a single chamber system. Not only SiH4 but also SiH2Cl2 is one of possible candidates for fabricating Si thin film solar cells.