纳米晶粒团聚GaN纳米线A1(LO) Raman峰的非对称展宽

氮化镓(GaN)是一种直接带隙Ⅲ～Ⅴ族半导体化合物,具有较宽的禁带宽度(Eg=3.4eV),较高的热稳定性,以及抗辐照等特性1-4],是制备近紫外和蓝光光电子器件、高速微电子器件的理想材料.制备低维纳米结构,研究其物理性质既是理解低维量子现象的要求,也是未来纳米电子器件发展的需要.近年来,很多小组已经通过不同的方法成功地制备出GaN纳米棒、纳米线等一系列一维材料.这些方法包括碳纳米管辅助的方法5]、电弧放电的方法6]、激光刻蚀的方法7]、升华法8]、高温分解法以及化学气相沉积(CVD)9-15].其中CVD方法以其制备过程简单,制备材料晶…

Asymmetric Broadening of A1(LO) Raman Peak of Nanocrystal Aggregated GaN Nanowires

Novel GaN nanowires were synthesized by a chemical vapor deposition (CVD) method. The morphology and structure of the nanowires were investigated by SEM, XRD and Raman spectra. Results show that GaN nanowires are formed by aggregated GaN nanocrystals, which is due to the non-uniform precipitation of GaN from catalyst droplet. An asymmetric broadening and shifting to lower frequency of A1(LO) peak are observed in the Raman spectra, which mainly contribute to the Fano interference between scattering from the k=0 optic phonon and electronic continuum scattering from laser-induced electrons.