Phase Control and Stability of Thin Silicon Films Deposited from Silane Diluted with Hydrogen

Abstract

AbstractHydrogen dilution of silane during the rf-PECVD growth of a-Si:H absorber layers is used to suppress light-induced degradation of a-Si:H solar cells. The increased stability of cells and films deposited using hydrogen dilution is verified in an accelerated degradation experiment. At higher hydrogen dilutions the early phase transition to the microcrystalline phase complicates the growth of fully amorphous films as absorbers with a sufficient thickness. In a systematic study on the influence of various deposition conditions on the material properties the pressure is identified as an important factor for controlling the structural phase evolution of the films.