Study on energy band of InGaN/GaN self-assembled quantum dots by deep-level transient spectroscopy

We characterized the energy band of an In-rich InGaN/GaN quantum dot (QD) system with a metal-insulator-semiconductor (MIS) structure by per-forming optical and electrical measurements. We found several electron traps that have the activation energies of 0.16, 0.40, 0.61, and 0.73eV with the emission cross sections of 2.16 x 10(-19), 2.23 x 10(-16), 8.61 x 10(-15) and 3.04 x 10(-16) cm(2), respectively. The origins of the traps were considered to be an N-vacancy, a QD state, an anti-site point defect and an interface state of the MIS structure. The bound state of QDs was determined to be 0.40 eV from the edge of the GaN barrier and had a capture barrier of 0.16eV generated by strain between the InGaN and GaN materials.