Influence of oxygen on the photoluminescence intensity of erbium (at 1.54 μm) in erbium-doped a-Si:H films

The influence of oxygen on photoluminescence (PL) of erbium (at 1.54 mu m) in erbium-doped hydrogenated amorphous silicon (c-Si[Er]) is investigated. The a-Si:H[Er] films studied are fabricated by cosputtering Si and Er targets using the technology of dc silane decomposition in a magnetic field. The oxygen concentration is varied from 10(19) to 10(21) cm(-3) by increasing the partial pressure of oxygen in the chamber. It is shown that, as in the case of erbium-doped crystalline silicon (c-Si[Er]), oxygen has an effect on the intensity of the 1.54 mu m photoluminescence in a-Si: H[Er] films. The values of the erbium and oxygen concentrations at which the maximum Er PL intensity is observed are two orders of magnitude higher than in crystalline silicon. The increase in the Er PL intensity at room temperature and the weaker temperature dependence of the Er PL in comparison to c-Si[Er,O] attest to the prospect of using a-Si: H[Er] films in optoelectronic applications. (C) 1998 American Institute of Physics. [S1063-7826(98)01811-0].