Chen Y T, Karlsson K F, Birch J, Holtz P O
Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden.
Sci Rep. 2016 Feb 15;6:21482. doi: 10.1038/srep21482.
Direct measurements of carrier diffusion in GaN nanorods with a designed InGaN/GaN layer-in-a-wire structure by scanning near-field optical microscopy (SNOM) were performed at liquid-helium temperatures of 10 K. Without an applied voltage, intrinsic diffusion lengths of photo-excited carriers were measured as the diameters of the nanorods differ from 50 to 800 nm. The critical diameter of nanorods for carrier diffusion is concluded as 170 nm with a statistical approach. Photoluminescence spectra were acquired for different positions of the SNOM tip on the nanorod, corresponding to the origins of the well-defined luminescence peaks, each being related to recombination-centers. The phenomenon originated from surface oxide by direct comparison of two nanorods with similar diameters in a single map has been observed and investigated.
利用扫描近场光学显微镜（SNOM）在10K的液氦温度下，对具有设计的InGaN/GaN线中分层结构的GaN纳米棒中的载流子扩散进行了直接测量。在没有施加电压的情况下，随着纳米棒直径从50纳米变化到800纳米，测量了光激发载流子的本征扩散长度。采用统计方法得出载流子扩散的纳米棒临界直径为170纳米。在纳米棒上SNOM针尖的不同位置采集了光致发光光谱，对应于明确定义的发光峰的起源，每个峰都与复合中心有关。通过在单张图谱中对两根直径相似的纳米棒进行直接比较，观察并研究了源自表面氧化物的现象。
