High current-induced degradation of AlGaN ultraviolet light emitting diodes
2011 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 109, no 10, 103108- p.Article in journal (Refereed) Published
Degradation under high current stress of AlGaN quantum well based light emitting diodes emitting at 285 and 310 nm has been studied using electroluminescence, time-resolved photoluminescence and current-voltage experimental techniques. The measurements have revealed that during aging decrease of the emission intensity is accompanied by increase of the tunneling current, increase of the nitrogen vacancy concentration and partial compensation of the p-doping. The main role in the device degradation has been ascribed to formation of tunneling conductivity channels, probably, via activation of the closed core screw dislocations with the help of nitrogen vacancies. Carrier lifetimes in the quantum wells and the p-cladding were found to be unaffected by the aging process, suggesting that the nonradiative recombination has a lesser influence on the device degradation.
Place, publisher, year, edition, pages
2011. Vol. 109, no 10, 103108- p.
GAN, NM, DISLOCATIONS, RELIABILITY, MECHANISMS, EMISSION, GROWTH, LEDS
IdentifiersURN: urn:nbn:se:kth:diva-36236DOI: 10.1063/1.3590149ISI: 000292115900033ScopusID: 2-s2.0-79958820030OAI: oai:DiVA.org:kth-36236DiVA: diva2:430627
QC 201107112011-07-112011-07-112011-08-30Bibliographically approved