Document Type

Article

Original Publication Date

2009

Journal/Book/Conference Title

Applied Physics Letters

Volume

95

Issue

20

DOI of Original Publication

10.1063/1.3266833

Comments

Originally published at http://dx.doi.org/10.1063/1.3266833

Date of Submission

April 2015

Abstract

The internal quantum efficiency(IQE) and relative external quantum efficiency (EQE) in InGaNlight-emitting diodes(LEDs) emitting at 400 nm with and without electron blocking layers (EBLs) on c-plane GaN and m-plane GaN were investigated in order to shed some light on any effect of polarizationcharge induced field on efficiency killer carrier spillover. Without an EBL the EQE values suffered considerably (by 80%) for both orientations, which is clearly attributable to carrier spillover. Substantial carrier spillover in both polarities, therefore, suggests that the polarizationcharge is not the major factor in efficiency degradation observed, particularly at high injection levels. Furthermore, the m-plane variety with EBL did not show any discernable efficiency degradation up to a maximum current density of 2250 A cm−2 employed while that on c-plane showed a reduction by ∼40%. In addition, IQE of m-plane LED structure determined from excitation power dependent photoluminescence was ∼80% compared to 50% in c-plane LEDs under resonant and moderate excitation condition. This too is indicative of the superiority of m-plane LED structures, most probably due to relatively larger optical matrix elements for m-plane orientation.

Rights

Lee, J., Li, X., Ni, X., et al. On carrier spillover in c- and m-plane InGaN light emitting diodes. Applied Physics Letters, 95, 201113 (2009). Copyright © 2009 AIP Publishing LLC.

Is Part Of

VCU Electrical and Computer Engineering Publications

Share

COinS