Wu Shaoteng, Wang Liancheng, Yi Xiaoyan, Liu Zhiqiang, Yan Jianchang, Yuan Guodong, Wei Tongbo, Wang Junxi, Li Jinmin
College of Materials Sciences and Opto-Electronic Technology, University of Chinese Academy of Sciences No. 19A Yuquan Road Beijing 100049 China
Research and Development Center for Semiconductor Lighting, Chinese Academy of Sciences No. 35A Qinghua East Road Beijing 100083 China.
RSC Adv. 2018 Jan 9;8(4):2181-2187. doi: 10.1039/c7ra11408g. eCollection 2018 Jan 5.
The optical and electrical properties of nitride materials are closely related to their crystallographic orientation. Here, we report our effort on crystallographic orientation manipulation of GaN NWs using vapour-liquid-solid hydride vapour phase epitaxy (VLS-HVPE). The growth orientations of the GaN NWs are tuned from the polar -axis to the non-polar -axis by simply varying the supply of III precursors on various substrates, including -, , -plane sapphire, (111) silicon and (0001) GaN. By varying the size of the Ni/Au catalyst, we found that the catalyst size has a negligible influence on the growth orientation of GaN NWs. All these demonstrate that the growth orientation of the GaN NWs is dominated by the flow rate of the precursor, regardless of the catalyst size and the substrate adopted. Moreover, the optical properties of GaN NWs were characterized using micro-photoluminescence, revealing that the observed red luminescence band (near 660 nm) is related to the lateral growth of the GaN NWs. The work presented here will advance the understanding of the VLS process of GaN NWs and represents a step forward towards controllable GaN NW growth.
氮化物材料的光学和电学性质与其晶体取向密切相关。在此，我们报告了我们利用气-液-固氢化物气相外延（VLS-HVPE）对氮化镓纳米线（GaN NWs）晶体取向进行调控的工作。通过简单地改变在包括α-、β-、γ-平面蓝宝石、（111）硅和（0001）氮化镓等各种衬底上III族前驱体的供应，氮化镓纳米线的生长取向从极性轴调整到非极性轴。通过改变镍/金催化剂的尺寸，我们发现催化剂尺寸对氮化镓纳米线的生长取向影响可忽略不计。所有这些都表明，氮化镓纳米线的生长取向由前驱体的流速主导，而与催化剂尺寸和所采用的衬底无关。此外，利用微光致发光对氮化镓纳米线的光学性质进行了表征，结果表明观察到的红色发光带（近660纳米）与氮化镓纳米线的横向生长有关。本文所展示的工作将增进对氮化镓纳米线VLS过程的理解，并代表了向可控氮化镓纳米线生长迈出的一步。
