Efficient passivation and size control of Si nanograins with stable photoluminescence

Abstract

ABSTRACT The Si-rich a-SiN x films are synthesized by pulsed laser ablation of silicon target under NH 3 atmosphere. By using laser-induced crystallization technique, the fabrication of nc-Si embedded in the SiN x is also realized. The crystallinity and microstructure of the films after laser annealing are characterized by scanning electron microscopy and micro-Raman spectroscopy. Additionally, in order to investigate the role of the SiN x on protecting the nc-Si from the oxidation in the air, the energy diffraction X-ray spectrum is also carried out. By photoluminescence (PL) spectrum measurement, the PL peak blue shifting is observed at room temperature. The results suggest that nc-Si embedded in the silicon nitride could be effectively passivated and stable PL of nasnosilicon grains could be obtained. Key words: passivation, crystallization, stable photolumi nescence 1. INTRODUCTION Nanoscaled silicon with visible light emission is a promising optoelectronic material because of its possible application in silicon-based integrated optoelectronic devices. Whereas there is a large percentage of surface-exposed atoms with dangling bands in the silicon grain, which would make it sensitive to the impurity in the air and would have a negative effect on its properties of photoluminescence