Intersubband Transition at 1.52 µm in GaN/AlN Multiple Quantum Wells Grown by Metal Organic Vapor Phase Epitaxy

Abstract

We have achieved the intersubband transition at 1.52 µm in metal organic vapor phase epitaxy (MOVPE) grown 40-period GaN (1.4 nm)/AlN (4.3 nm) multiple quantum wells (MQWs). Two breakthroughs led us to this achievement: (1) the low temperature growth of MQWs at 830 °C on a high-quality AlGaN/AlN template grown at higher temperatures led to excellent GaN/AlN interfaces, and (2) reduction of carbon impurity in the GaN wells by pulse injection method resulted in a carrier density as high as 2×1019 cm-3 in spite of the low temperature growth. A strong absorption peak at 1.52 µm with a full-width at half-maximum of 113 meV was clearly observed at room temperature.