Document Type

Article

Original Publication Date

2010

Journal/Book/Conference Title

Applied Physics Letters

Volume

97

Issue

3

DOI of Original Publication

10.1063/1.3465658

Comments

Originally published at http://dx.doi.org/10.1063/1.3465658

Date of Submission

April 2015

Abstract

Ballistic and quasiballistic electron transport across the active InGaN layer are shown to be responsible for electron overflow and electroluminescence efficiency droop at high current levels in InGaN light emitting diodes both experimentally and by first-order calculations. An InGaN staircase electron injector with step-like increased In composition, an “electron cooler,” is proposed for an enhanced thermalization of the injected hot electrons to reduce the overflow and mitigate the efficiency droop. The experimental data show that the staircase electron injector results in essentially the same electroluminescence performance for the diodes with and without an electron blocking layer, confirming substantial electron thermalization. On the other hand, if no InGaN staircase electron injector is employed, the diodes without the electron blocking layer have shown significantly lower (three to five times) electroluminescence intensity than the diodes with the blocking layer. These results demonstrate a feasible method for the elimination of electron overflow across the active region, and therefore, the efficiency droop in InGaN light emitting diodes.

Rights

Ni, X., Li, X., Lee, J., et al. InGaN staircase electron injector for reduction of electron overflow in InGaN light emitting diodes. Applied Physics Letters, 97, 031110 (2010). Copyright © 2010 AIP Publishing LLC.

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VCU Electrical and Computer Engineering Publications

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