Lin Fang, Liao Xin, Liu Chuan-Pu, Zhang Zhen-Sheng, Liu Song, Yu Dapeng, Liao Zhi-Min
State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China.
Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Omega. 2020 Feb 21;5(8):4133-4138. doi: 10.1021/acsomega.9b03858. eCollection 2020 Mar 3.
We report on a high-brightness ultraviolet (UV) nanoscale light source. The light emission diodes are constructed with graphene/ZnO nanowire/p-GaN vertical junctions, which exhibit strong UV electroluminescence (EL) emissions centered at a wavelength of 397 nm at one end of the ZnO nanowire. Compared to the horizontal heterojunction, the vertical junction based on the ZnO nanowire increases the interface area of the heterojunction along with a high-quality interface, thus making the device robust under a large excitation current. In this structure, transparent flexible graphene is used as the top electrode, which can effectively improve performance by increasing the carrier injection area. Moreover, by analyzing the relationship between the integrated light intensity and applied bias, a superlinear dependency with a slope of 3.99 is observed, which means high electrical-to-optical conversion efficiency. Three electron-hole irradiation recombination processes are distinguished according to the EL emission spectra.
我们报道了一种高亮度紫外（UV）纳米级光源。发光二极管由石墨烯/氧化锌纳米线/p型氮化镓垂直结构成，在氧化锌纳米线的一端呈现出以397纳米波长为中心的强烈紫外电致发光（EL）发射。与水平异质结相比，基于氧化锌纳米线的垂直结增加了异质结的界面面积以及高质量的界面，从而使器件在大激发电流下具有鲁棒性。在这种结构中，透明柔性石墨烯用作顶部电极，通过增加载流子注入面积可有效提高性能。此外，通过分析积分光强与施加偏压之间的关系，观察到斜率为3.99的超线性依赖关系，这意味着具有高的电光转换效率。根据EL发射光谱区分出三种电子-空穴辐照复合过程。
