Defect-related contributions to the reduction of the internal quantum efficiency of InGaN-based multiple quantum well light emitting diodes under high forward bias conditions were considered. Screening of localization potentials for electrons was an important process to reduce the localization at high injection. The possible role of threading dislocations in inducing a parasitic tunnelling current in the device was discussed. Phonon-assisted transport of holes via tunnelling at defect sites along dislocations was suggested to be involved, leading to a non-radiative parasitic process enhanced by a local temperature rise at high injection.

Defect Related Issues in the “Current Roll-Off” in InGaN Based Light Emitting Diodes. B.Monemar, B.E.Sernelius: Applied Physics Letters, 2007, 91[18], 181103