Performance of Nanostructures within InGaN-Based Multiquantum-Well Light-Emitting Devices

Ya-Fen Wu,Jiunn-Chyi Lee

doi:10.3390/app7040380

Abstract

We introduced multiquantum-barrier (MQB) nanostructures into the barrier layers of InGaN/GaN multiquantum-well (MQW) heterostructures to improve the operation characteristics of the light-emitting devices. The electroluminescence (EL) spectra were examined over a broad range of temperatures for the samples. We observed inhibited carrier leakage for the sample with the MQB nanostructures. Greater inhomogeneity of nanocrystallite size and a stronger localization effect were also observed for the sample. To interpret this phenomenon, high-resolution X-ray diffraction curves were measured and analyzed using the Warren–Averbach model. External quantum efficiency as a function of temperature was also evaluated. The calculation results correspond with the inference the EL measurements provided. We determined that the performance of the light-emitting devices is enhanced by the MQB nanostructures within InGaN/GaN MQWs.

Highlights

III–N compound semiconductors have been used in a wide range of applications because of their broad applications in the fabrication of light-emitting diodes (LEDs), laser diodes (LDs), solar cells, and photodetectors, which emit over a broad spectral range from infrared to ultraviolet [1,2,3]
Much interest has been focused on InGaN/GaN multiquantum wells (MQWs) because they can act as the active layer in high-brightness III-N LEDs and blue and green LDs [3,4]
We investigated the performance of InGaN/GaN MQW light‐emitting devices

Summary

Introduction

III–N compound semiconductors have been used in a wide range of applications because of their broad applications in the fabrication of light-emitting diodes (LEDs), laser diodes (LDs), solar cells, and photodetectors, which emit over a broad spectral range from infrared to ultraviolet [1,2,3].Much interest has been focused on InGaN/GaN multiquantum wells (MQWs) because they can act as the active layer in high-brightness III-N LEDs and blue and green LDs [3,4]. Some methods have been suggested to address the reduced overlap integral between the electron and hole wave functions, including polarization band engineering [5], developing InGaN LEDs on GaN templates with nonpolar or semipolar crystal orientations [6,7]; the improvement of internal quantum efficiency can be achieved. InGaN/GaN MQW devices must deal with the requirements of high current injection. Their performance decreases significantly as the operating current density increases. It was reported that Auger recombination plays an important role in the efficiency droop of MQW LEDs at high current density, a dilute-As GaNAs material with negligible interband Auger process was proposed recently as a possible material to solve the problem [10,11,12,13].

Methods

Results

Conclusion