Control of crystalline quality of MOVPE-grown GaN and (Al,Ga)N/AlGaN MQW using In-doping and/or N-2 carrier gas

The effects of isoelectronic In-doping on the structural and optical proper ties of GaN, GaN/Al0.17Ga0.83N and Al0.05Ga0.95N/Al0.17Ga0.83N quantum well s (QWs) on GaN were investigated. QWs were grown by atmospheric pressure me talorganic vapor-phase epitaxy with either H-2 or N-2 carrier gas. Without In-doping, QWs grown in N-2 carrier gas had much higher crystalline and opt ical properties than those grown in H, carrier gas. X-ray diffraction and p hotoluminescence studies have revealed that In-doping improves the crystall ine and optical properties of QWs, regardless of the carrier gas species us ed during growth. These improvements are more remarkable for In-doping into the well layers rather than into the barrier layers. (C) 2000 Elsevier Sci ence B.V. All rights reserved.