a-Si_3N_4纳米粒子的激光法制备及能级结构研究

A STUDY ON LASER-PREPARATION AND ENERGY- LEVEL STRUCTURE OF NANOMETER SIZED a-Si,N4 PARTICLES

给出激光化学汽相沉积法制备ａ－Ｓｉ３Ｎ４纳米粒子的原理和经验公式，在特定工艺参数下获得平均粒径为６．５ｎｍ的优质ａ－Ｓｉ３Ｎ４纳米粒子，用紫外光谱研究其能级结构，发现与小粒子有关的峰状光谱结构和能带分裂现象，描述了ａ－Ｓｉ３Ｎ４纳米粒子的物理结构图象，确认硅错键≡Ｓｉ－Ｓｉ≡，硅悬挂键≡Ｓｉ＾０３，在富硅ａ－Ｓｉ３Ｎ４纳米粒子光谱性质中的主导作用。

In this paper, we give the principle and the empirical formulas of the preparation for nanometer sized a-Si3N4 particles by laser induced chemical vapor deposition (LICVD). Under certain technological parameters, our experiments have obtained high quality nanometer a-Si3N4 particles whose average diameter is 6.5nm. We disperse these particles in organic solvent so as to study its energy level structure with ultravolet-visible spectrum. The photoluminescent experiments show its peak-like spectrum structure and the splitting of energy band, which relate to super micro-particles. We also describe the picture of the physical structure of nanometer a-Si3N4 particles and demonstrate that silicon'wrong bond'≡Si-Si≡and silicon dangling bond≡Si30 play a dominant role in the spectrum character for Si-riched nanometer a-Si,N, particle.