Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

Zhanxu Chen,Chongjun Jin,Baijun Zhang,Yongzhu Chen,Wei Wan,Gengyan Chen,Wenjie Liu

doi:10.1155/2016/8202405

Abstract

The indium tin oxide (ITO) has been widely applied in light emitting diodes (LEDs) as the transparent current spreading layer. In this work, the performance of GaN-based blue light LEDs with nanopatterned ITO electrode is investigated. Periodic nanopillar ITO arrays are fabricated by inductive coupled plasma etching with the mask of polystyrene nanosphere. The light extraction efficiency (LEE) of LEDs can be improved by nanopatterned ITO ohmic contacts. The light output intensity of the fabricated LEDs with nanopatterned ITO electrode is 17% higher than that of the conventional LEDs at an injection current of 100 mA. Three-dimensional finite difference time domain simulation matches well with the experimental result. This method may serve as a practical approach to improving the LEE of the LEDs.

Highlights

GaN-based light emitting diodes (LEDs) have been garnering an increasing amount of attention in the field of solid state lighting, signaling, and displays due to their broad emission wavelength range [1]
When considering LEDs lighting as a replacement for fluorescent lighting, their light extraction efficiency (LEE) is still relatively low due to the internal total reflection of light trapped inside LEDs [2]
In order to explore the different effects of various indium tin oxide (ITO) nanopillar structure on LEE of the LED, three nanopatterned ITO samples were fabricated by different inductively coupled plasma (ICP) etching time

Summary

Introduction

GaN-based light emitting diodes (LEDs) have been garnering an increasing amount of attention in the field of solid state lighting, signaling, and displays due to their broad emission wavelength range [1]. Roughed GaN surface [3,4,5,6,7], roughed sapphire substrate [8, 9], roughed indium tin oxide (ITO) surface [10,11,12], and grown ZnO micro-/nanostructures [13,14,15] have been implemented in LEDs. The common nanoscale patterning techniques, such as electron-beam lithography [16], nanoimprint lithography [17], holographic lithography [18], hydrothermally method [19], and nanosphere lithography (NSL) [20], are used to obtain nanoscale surface textures.

Methods

Results

Conclusion