The strong blue-shifted photoluminescence from amorphous silicon-nitride (a-SiNx:H) layers prepared by PECVD method

In this study, the a-SiNx: H thin films were produced by the plasma enhanced chemical vapor deposition (PECVD) method. The photoluminescence at room temperature with the different SiH4/N-2 gas flow ratio was investigated in this work. The peaks of photoluminescence spectra were demonstrated obvious blue-shifted from the 830 nm to the 430 nm with increasing the nitrogen flow rate. Further annealing the sample at 700 degrees C for 10 min, the peaks have evidenced red-shifted about 50 nm. The X-ray photoelectron spectra (XPS) were applied to determine the configuration of the a-SiNx: H thin films. The peak of Si 2p binding energy shift from 99.7 eV toward the 102 eV. The silicon clusters and multi-phase existing in the thin films were suggested from the random bonding model. Further from the blue-shifted of the PL emission and the redshifted of the annealing results. The optical emission may come hom the alloy phase of the silicon embedded a-SiNx:H thin films.