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

The fabrication of p–i–n Si thin film solar cells using a SiH ₂Cl ₂–H ₂ mixture by rf plasma-enhanced chemical vapor deposition is presented. A novel p-type nanocrystalline Si:H:Cl film was synthesized from H ₂-diluted SiH ₂Cl ₂ and SiCl ₄ 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 ⁻⁶ S/cm under 100 mW/cm ² white light exposure. The efficiency of 6.2% has been achieved in the p–i–n solar cells fabricated from a SiH ₂Cl ₂–H ₂ mixture at T _s of 340 °C for the first time despite a use of a single chamber system. Not only SiH ₄ but also SiH ₂Cl ₂ is one of possible candidates for fabricating Si thin film solar cells.