Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Duisburg, Germany.
Nanotechnology. 2011 Feb 25;22(8):085702. doi: 10.1088/0957-4484/22/8/085702. Epub 2011 Jan 17.
We present GaAs electroluminescent nanowire structures fabricated by metal organic vapor phase epitaxy. Electroluminescent structures were realized in both axial pn-junctions in single GaAs nanowires and free-standing nanowire arrays with a pn-junction formed between nanowires and substrate, respectively. The electroluminescence emission peak from single nanowire pn-junctions at 10 K was registered at an energy of around 1.32 eV and shifted to 1.4 eV with an increasing current. The line is attributed to the recombination in the compensated region present in the nanowire due to the memory effect of the vapor-liquid-solid growth mechanism. Arrayed nanowire electroluminescent structures with a pn-junction formed between nanowires and substrate demonstrated at 5 K a strong electroluminescence peak at 1.488 eV and two shoulder peaks at 1.455 and 1.519 eV. The main emission line was attributed to the recombination in the p-doped GaAs. The other two lines correspond to the tunneling-assisted photon emission and band-edge recombination in the abrupt junction, respectively. Electroluminescence spectra are compared with the micro-photoluminescence spectra taken along the single p-, n- and single nanowire pn-junctions to find the origin of the electroluminescence peaks, the distribution of doping species and the sharpness of the junctions.
我们展示了通过金属有机气相外延法制造的 GaAs 电致发光纳米线结构。在单个 GaAs 纳米线中的轴向 pn 结和纳米线与衬底之间形成 pn 结的独立纳米线阵列中，分别实现了电致发光结构。在 10 K 下，从单根纳米线 pn 结发出的电致发光发射峰的能量约为 1.32 eV，并随着电流的增加而移至 1.4 eV。该线归因于由于汽-液-固生长机制的记忆效应，在纳米线中存在的补偿区域中的复合。在纳米线与衬底之间形成 pn 结的阵列纳米线电致发光结构在 5 K 下显示出强烈的 1.488 eV 电致发光峰，以及 1.455 和 1.519 eV 的两个肩峰。主要发射线归因于 p 掺杂 GaAs 中的复合。其他两条线分别对应于隧道辅助光子发射和突变结中的能带边缘复合。将电致发光光谱与沿单个 p-、n-和单个纳米线 pn 结获得的微光致发光光谱进行比较，以找到电致发光峰的起源、掺杂物种的分布和结的锐度。
