MOCVD自催化法在Si(100)衬底上生长InP/InGaAs核壳结构纳米线

The Catalyst-free InP/InGaAs Core-shell Nanowires Growth on Silicon by Metal Organic Chemical Vapor Deposition

采用自催化法,利用金属有机化学气相沉积技术,在Si(100)衬底上成功制备了InP/InGaAs核壳结构纳米线。通过扫描电子显微镜观察纳米线形貌,在核壳结构纳米线的顶端催化剂转化成了颗粒状晶体。利用X射线衍射和透射电子显微镜研究了InP纳米线上生长InGaAs外壳的过程,并应用X射线能量色散能谱仪对纳米线顶端进行了轴向和径向的线扫描,得到了纳米线上元素组分分布。催化剂的转化发生在制备InGaAs壳之前的升温过程中,且形成的晶体中含有合金成分。InGaAs壳的组分调整可以通过改变生长过程中生长源气体的流量来实现。

Catalyst-free InP/InGaAs core-shell nanowires were grown on Si（100） substrates by metal-organic chemical vapor deposition.These nanowires have quite different properties to Au-catalyst core-shell nanowires.By using scanning electron microscope,we found that the catalyst at the top of the InP nanowires had been transformed into crystal after the InGaAs core grown on them.Meanwhile,the diameter of the nanowires has greatly increased with their length changed quite little.The X-ray diffraction patterns indicate that the transformation of the catalyst is attributed to the temperature rise under PH3 protection before InGaAs core growth.By transmission electron microscope and energy dispersive X-ray spectroscopy,it is proved that the transformation of catalyst is prior to the InGaAs core growth and is cover by InGaAs which is same to the nanowires sidewall.