Analysis of V defects in GaN-based light emitting diodes by scanning transmission electron microscopy and electron beam induced current

In the fabrication of InGaN/GaN multiple quantum well light emitting diodes so-called V defects are common, but little is known about their electrical activity. Scanning transmission electron microscopy is capable of directly observing these defects, while electron beam induced current (EBIC) techniques can be used to probe electronic behavior of semiconductor defects. These techniques were combined to obtain localized measurements and our results indicate that V defects suppress the EBIC signal near the core of the defect and produce a displacement in the p-n junction location. Furthermore, the EBIC profile suggests that minority carrier diffusion lengths are longer inside the defect. (C) 2008 American Institute of Physics.