Effects of embedded crystallites in amorphous silicon on light-induced defect creation

Abstract
We investigate effects of embedded crystallites in hydrogenated amorphous silicon on light-induced metastable dangling-bond defect creation in a systematic manner. Inclusion of a small volume fraction of crystallites into the amorphous matrix significantly suppresses defect creation against moderate light illumination. Excess carriers generated in the amorphous matrix tend to recombine in the embedded crystallites, which suppresses nonradiative recombination within the amorphous matrix and the subsequent defect creation. The presence of a small volume fraction of crystallites, however, is no longer effective to improve the stability against strong light exposure such as pulsed laser irradiation. In this case, the higher carrier concentration favors bimolecular direct carrier recombination within the amorphous matrix.