Properties of Sub-Band Edge States in AlInN Studied by Time-Resolved Photoluminescence of a AlInN/GaN Heterostructure

Time-resolved photoluminescence (PL) measurements of Al0.82In0.18N/GaN heterostructures revealed a large enhancement of low temperature PL from the GaN layer and a strong temperature dependence of this effect. Analysis of different phenomena that might affect the photoexcited carrier dynamics suggests that the enhanced GaN PL should be attributed to photoexcited hole transfer from the AlInN layer. The hole transport most probably takes place via dense sub-band edge valence band states related to nanoscale In-rich clusters. Scanning near-field optical microscopy data support this assignment.