Degradation of InGaN/GaN laser diodes investigated by micro-cathodoluminescence and micro-photoluminescence

M. MENEGHINI;S. CARRARO;G. MENEGHESSO;N. TRIVELLIN;MURA, GIOVANNA;F. ROSSI;G. SALVIATI;K. HOLC;T. WEIG;L. SCHADE;M. A. KARUNAKARAN;J. WAGNER;U. T. SCHWARZ;AND E. ZANONI

2013-01-01

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Abstract

We present an investigation of the degradation of InGaN/GaN laser diodes grown on a GaN substrate. The results indicate that: (i) Ageing induces a significant increase in the threshold current (Ith) of the lasers, which is attributed to an increase in non-radiative recombination; (ii) Ith increase is correlated to a decrease in the micro-cathodoluminescence signal measured (after the removal of the top metallization) in the region under the ridge; (iii) micro-photoluminescence measurements indicate that constant current stress increases non-radiative recombination within the quantum wells (and not only within the barriers), and induces an increase in the emission wavelength of the degraded region