p-GaN/n-ZnO heterojunction nanowires: optoelectronic properties and the role of interface polarity.
p-GaN/n-ZnO heterojunction nanowires: optoelectronic properties and the role of interface polarity.
复制标题
DOI：
10.1021/nn406134e
复制
发表时间：
2014-04
期刊：
影响因子：
17.1
通讯作者：
F. Schuster;B. Laumer;R. Zamani;C. Magén;J. Morante;J. Arbiol;M. Stutzmann
中科院分区：
文献类型：
--
作者：
F. Schuster;B. Laumer;R. Zamani;C. Magén;J. Morante;J. Arbiol;M. Stutzmann
在这项工作中，提出了 p-GaN/n-ZnO 异质界面的电子能带结构的模拟。与同质结相反，由于 II 型能带排列而产生的额外能量势垒阻碍了该异质结中大多数电荷载流子的流动。自发极化和压电性被证明还会影响能带结构和复合区域的位置。 p-GaN/n-ZnO 异质结纳米线被提议作为潜在的 UV-LED 和激光二极管，通过等离子体辅助分子束外延 (PAMBE) 制造。原子分辨率环形明场扫描透射电子显微镜 (STEM) 研究揭示了一种突变且无缺陷的异质界面，其极性从 N 极性 GaN 反转为 Zn 极性 ZnO。光致发光测量显示出源自界面 ZnO 侧的强激子紫外发射，以及在光泵浦阈值高于 55 kW/cm(2) 的情况下的受激发射。
In this work, simulations of the electronic band structure of a p-GaN/n-ZnO heterointerface are presented. In contrast to homojunctions, an additional energy barrier due to the type-II band alignment hinders the flow of majority charge carriers in this heterojunction. Spontaneous polarization and piezoelectricity are shown to additionally affect the band structure and the location of the recombination region. Proposed as potential UV-LEDs and laser diodes, p-GaN/n-ZnO heterojunction nanowires were fabricated by plasma-assisted molecular beam epitaxy (PAMBE). Atomic resolution annular bright field scanning transmission electron microscopy (STEM) studies reveal an abrupt and defect-free heterointerface with a polarity inversion from N-polar GaN to Zn-polar ZnO. Photoluminescence measurements show strong excitonic UV emission originating from the ZnO-side of the interface as well as stimulated emission in the case of optical pumping above a threshold of 55 kW/cm(2).