Evidence of optically induced degradation in gallium nitride optoelectronic devices

Carlo de Santi (1) , Alessandro Caria (1) , Nicola Renso (1) , Ezgi Dogmus (2) , Malek Zegaoui (2) , F Medjdoub (2, 3) , Gaudenzio Meneghesso (1) , Enrico Zanoni (1) , Matteo Meneghini (1)

1 DEI - Department of Information Engineering [Padova]
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 WIND - IEMN - WIde baNd gap materials and Devices - IEMN

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.

Domaines: Micro et nanotechnologies/Microélectronique

Carlo de Santi, Alessandro Caria, Nicola Renso, Ezgi Dogmus, Malek Zegaoui, et al.. Evidence of optically induced degradation in gallium nitride optoelectronic devices. Applied Physics Express, 2018, 11 (11), pp.111002. ⟨10.7567/APEX.11.111002⟩. ⟨hal-02356737⟩