Degradation mechanisms and lifetime of state-of-the-art green laser diodes

Marioli, M;Meneghini, M;Rossi, F;Salviati, G;de Santi, C;MURA, GIOVANNA;Meneghesso, G;Zanoni E.

2015-01-01

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Abstract

This paper presents a detailed analysis of the degradation kinetics and of the reliability of state-of-the-art InGaN-based green laser diodes (LDs), submitted to CW stress tests at different operating conditions. Results described in the following indicate that: (i) constant current stress induces an increase in threshold current (Ith), which is well correlated to a decrease in the sub-threshold emission; (ii) the Ith increase has a power law dependence on stress time; (iii) the degradation rate is strongly dependent on the stress current level while it does not significantly depend on the optical field in the cavity; (iv) stress temperature acts as an accelerating factor for LDs degradation; the activation energy of the degradation process is equal to 258 meV; (v) pure thermal storage does not induce a significant degradation of device characteristics. Cathodoluminescence measurements were carried out to get more insight into the physical origin of the degradation process.