利用石墨烯量子点实现光子回收，提升 GaN 基紫外发光二极管性能。

Enhanced Performance of GaN-based Ultraviolet Light Emitting Diodes by Photon Recycling Using Graphene Quantum Dots.

机构信息

Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li, 32023, Taiwan.

Department of Photonics, Research Center Energy Technology and Strategy, National Cheng Kung University, Tainan, 701, Taiwan.

出版信息

Sci Rep. 2017 Aug 2;7(1):7108. doi: 10.1038/s41598-017-07483-3.

DOI:10.1038/s41598-017-07483-3

PMID:28769094

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5541035/

Abstract

Graphene quantum dots (GQDs) with an average diameter of 3.5 nm were prepared via pulsed laser ablation. The synthesized GQDs can improve the optical and electrical properties of InGaN/InAlGaN UV light emitting diodes (LEDs) remarkably. An enhancement of electroluminescence and a decrease of series resistance of LEDs were observed after incorporation of GQDs on the LED surface. As the GQD concentration is increased, the emitted light (series resistance) in the LED increases (decreases) accordingly. The light output power achieved a maximum increase as high as 71% after introducing GQDs with the concentration of 0.9 mg/ml. The improved performance of LEDs after the introduction of GQDs is explained by the photon recycling through the light extraction from the waveguide mode and the carrier transfer from GQDs to the active layer.

摘要

通过脉冲激光烧蚀制备了平均直径为 3.5nm 的石墨烯量子点（GQDs）。合成的 GQDs 可以显著提高 InGaN/InAlGaN 紫外发光二极管（LED）的光学和电学性能。在 LED 表面掺入 GQDs 后，观察到电致发光增强和串联电阻降低。随着 GQD 浓度的增加，LED 发出的光（串联电阻）相应增加（减少）。在引入浓度为 0.9mg/ml 的 GQDs 后，光输出功率实现了高达 71%的最大增加。引入 GQDs 后，LED 性能得到改善，这是通过从波导模式提取光和从 GQDs 到有源层的载流子转移进行光子回收来解释的。