Graphene/ZnO Nanowire/p-GaN Vertical Junction for a High-Performance Nanoscale Light Source

Fang Lin; Xin Liao; Chuan-Pu Liu; Zhen-Sheng Zhang; Song Liu; Dapeng Yu; Zhi-Min Liao

doi:10.1021/acsomega.9b03858

Graphene/ZnO Nanowire/p-GaN Vertical Junction for a High-Performance Nanoscale Light Source

ACS Omega. 2020 Feb 21;5(8):4133-4138. doi: 10.1021/acsomega.9b03858. eCollection 2020 Mar 3.

Authors

Fang Lin¹, Xin Liao¹, Chuan-Pu Liu¹, Zhen-Sheng Zhang², Song Liu², Dapeng Yu², Zhi-Min Liao^{1

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Affiliations

¹ State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China.
² Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
³ Beijing Key Laboratory of Quantum Devices, Peking University, Beijing 100871, China.
⁴ Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China.

Abstract

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.