Evidence of optically induced degradation in gallium nitride optoelectronic devices. (12th October 2018)

• Record Type: Journal Article
• Authors: De Santi, Carlo; Caria, Alessandro; Renso, Nicola; Dogmus, Ezgi; Zegaoui, Malek; Medjdoub, Farid; Meneghesso, Gaudenzio; Zanoni, Enrico; Meneghini, Matteo
• Is Part Of: Applied physics express. Volume 11:Number 11(2018)
• Publication Date: 2018-10-12
• Subjects: Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/APEX.11.111002
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We provide experimental evidence that gallium-nitride-based optoelectronic devices can be affected by a photon-driven degradation mechanism unrelated to catastrophic optical damage. Any role of current in such degradation is excluded by stress tests under laser irradiation in the open-circuit configuration; any role of temperature is ruled out by additional thermal tests, showing a different degradation mode. Given the high bond strength of GaN, lattice-damage-related degradation is unlikely. A possible cause, supported by the PL spectra, is the dehydrogenation of gallium vacancies, which causes an increase in the number of optically active defects and requires a removal energy lower than the photon energy.