Effects of surface migration on InGaN/GaN multiple quantum wells selectively grown on periodic stripe openings separated by large SiO2 covered spacing on Si (111) substrates

摘要

InGaN/GaN multiple quantum wells (MQWs) were selectively grown on patterned GaN/AlN/Si (111) templates with periodic stripe openings separated by large SiO2 covered spacing. In comparison with the conventional epitaxial lateral overgrowth, the migration behaviours of group-III adatoms on the large mask region has a distinct effect on the structural and optical properties of InGaN/GaN MQWs selectively grown on the narrow stripe openings. In order to control them, a wide stripe window nearby the narrow one was adopted to modulate the local growth environments in our experiment. Flat and faceted InGaN/GaN MQWs stripes with trapezoidal cross section composed of basal (0001) plane and two semipolar {1122} facets were obtained. The optical properties were investigated by the microscopic photoluminescence (micro-PL) measurement. The difference in emission peak positions observed by scanning the excitation laser across the stripes is related to the surface migration behaviour of the group-III adatoms on the SiO2 masks.