Localized states at InGaN/GaN quantum well interfaces

Low-energy electron-excited nanoscale-luminescence (LEEN) spectroscopy of G aN/InGaN/GaN double-heterojunction structures reveal the formation of elect ronic states localized near the quantum well interfaces under relatively In -rich conditions. These states are due to formation in a cubic GaN region c omparable to the quantum well layer in thickness rather than the bulk nativ e defects typically associated with growth quality. The nanoscale depth dep endence of the noncontact, nondestructive LEEN technique enables detection of this competitive recombination channel within a few nanometers of the "b uried" heterojunction interfaces. (C) 1999 American Institute of Physics. [ S0003-6951(99)01250-4].