Improvement in Electron Overflow of Near-Ultraviolet InGaN LEDs by Specific Design on Last Barrier

Abstract

Specific designs on the last barrier of near-ultraviolet InGaN light-emitting diodes are investigated numerically in order to diminish the electron leakage current without sacrificing the injection efficiency of holes. Due to the reduction of electron leakage current, the recombination of electrons and holes in the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -layers is decreased and, thus, more holes can be injected into the active region. The simulation results show that the optical performance and internal quantum efficiency are markedly improved when the last GaN barrier near the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -layers is partially replaced by In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.01</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.99</sub> N layer and intentionally <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -doped.