Inhomogeneity of InGaN quantum wells in GaN‐based blue laser diodes

Abstract

AbstractWe investigated the inhomogeniety of InGaN quantum wells (QWs) with high In content in the GaN‐based blue laser diodes (LDs). The 2QWs LD structure show the twice higher photoluminescence intensity and the slightly higher electroluminescence intensity than single quantum well (SQW) LD. However, we can obtain the high power blue InGaN SQW LDs with the low threshold current density of 2.19 kA/cm2 and the high sloped efficiency of 0.8 W/A at the cw condition by reducing the number of QWs. From carrier distribution by simulation, blue InGaN 2QWs LDs represented the non‐uniformed hole distribution of n‐side 1st and p‐side 2nd well in InGaN/InGaN 2QWs region due to the low hole concentration and mobility of p‐type nitrides. From time‐resolved photoluminescence (TRPL), we obtained that 2QWs LD shows the some spatial localization states due to the multiple component PL decay process. Therefore, we can guess that the inhomogeniety of InGaN QWs would be quite restricted in deep InGaN QWs of GaN based blue LDs which results in significantly in homogeneities of QWs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)