Minority-carrier diffusion length in a GaN-based light-emitting diode

Minority-carrier diffusion lengths of electrons and holes were measured in a GaN-based light-emitting diode using the electron-beam-induced current technique in the line-scan configuration. A theoretical model with an extended generation source and a nonzero surface recombination velocity was used to accurately extract the diffusion length of the p- and n-type layers. A minority-carrier diffusion length of L-n = (80 +/-6) nm for electrons in the p-type GaN layer, L-p = (70 +/-4) nm for holes in the n-type GaN:Si,Zn active layer, and L-n = (55 +/-4) nm for electrons in the p-type Al0.1Ga0.9N layer were determined. The results from this model are compared with two simpler and widely used theoretical models. (C) 2001 American Institute of Physics.