Kinetics and steady-states of light-induced defects in a-Si:H prepared by three different techniques

Abstract

Three different preparation techniques for hydrogenated amorphous silicon (a-Si:H), (1) the conventional plasma CVD method, (2) post-deposition annealing of a-Si:H prepared at a low deposition temperature, and (3) helium-dilution method, were employed to obtain a-Si:H with different microscopic/mesoscopic structures, of which light-induced metastability was investigated. Differences among the samples appeared in the steady-state defect density under illumination, its dependence on illumination temperature, and in thermal and light-induced annealing behaviors. They were interpreted in the framework of a defect-pool model, where the distributions of defect annealing energies depend on the film structure.