Dependence of electron mobility on spacer thickness and electron density in modulation-doped Ga0.47In0.53As/Al0.48In0.52As heterojunctions

Abstract

Modulation-doped Ga0.47In0.53As/Al0.48In0.52As heterojunctions were grown by molecular beam epitaxy. Electron mobilities were measured at room temperature and 77 K as a function of undoped Al0.48In0.52As spacer layer thickness and sheet carrier concentration. Enhanced mobilities were as high as 10 900 cm2V−1s−1 at room temperature and 55 500 cm2V−1s−1 at 77 K in these samples with sheet carrier concentrations at 1 33 × 1012 cm−2 (room temperature) and 1.26 × 1012 cm−12 (77 K).