Thermally induced photoluminescence quenching centre in hydrogenatedamorphous silicon oxynitride

Abstract

The effect of thermal annealing on the photoluminescence around 2.2-2.9 eV inhydrogenated amorphous silicon oxynitride films was investigated. Theluminescence intensity increases monotonically with an increase in theannealing temperature for the samples with lower nitrogen contents (N/O=0.06, 0.10 and 0.12). It shows a similar increase up to 500 °C, while it decreases abruptly above 500 °C for thesamples with higher nitrogen contents (N/O=0.14 and 0.18). The densityof silicon dangling bonds depends on the annealing temperature in a manneropposite to that of the luminescence intensity in all the temperature region.Based on this correlation, it is thought that the silicon dangling bonds actas the quenching centre. Infrared absorption spectroscopy indicated that theprecursor of silicon dangling bonds was the Si-H bond. Hydrogen was releasedat temperatures above 500 °C from Si-H bonds, resulting in a largenumber of silicon dangling bonds that quench the luminescence.