High electron mobility in metamorphic epitaxial InAs0.7Sb0.3 compound and its p-i-n photodetector

Our study explores growth techniques and the electrical/optical behavior of InAs0.7Sb0.3 compounds on GaAs substrates, utilizing various metamorphic buffer layers. The InAlSb graded-buffer layer emerged as the most promising, displaying a remarkable electron mobility of 26,370 cm/V∙s, a record high. It signifies excellent lateral crystal quality for room-temperature carrier transport. Meanwhile, the presence of micro-twins, evident in cross-sectional TEM images, degrades vertical crystal quality. We further assess crystal quality through low-temperature Hall mobility and photoresponses, featuring reduced bowing parameters. These findings offer valuable insights for optimizing metamorphic growth platforms for ternary InAsSb compounds.