Strong room-temperature photoluminescence of hydrogenated amorphous silicon oxide and its correlation to porous silicon

Abstract

A set of hydrogenated amorphous silicon oxide (a-SiOx:H) films have been fabricated by plasma enhanced chemical vapor deposition. Some of the films exhibit strong room-temperature photoluminescence and others do so only after annealing at high temperature. The variation of photoluminescence after different annealing treatments for these films is found to be similar to that of porous silicon. Assisted by infrared spectra it is concluded that the photoluminescence from a-SiOx:H is originated from the small a-Si clusters or microcrystalline silicon embedded in the amorphous SiOx network. This argument may support a similar model proposed to explain the visible photoluminescence of porous silicon.