Abstract
Modulation doped Ga 0.47 In 0.53 As-Al 0.48 In 0.52 As single-period heterostructures have been prepared by molecular beam epitaxy (MBE). Electron mobilities as high as 8915 cm 2 /V s at 300 K, 60 120 cm 2 /V s at 77 K, and 90 420 cm 2 /V s at 10 K were obtained with an average electron concentration of ∼10 17 cm -3 . These results represent a mobility enhancement over uniformly doped Ga 0.47 In 0.53 As with the same carrier concentration by about a factor of 6 at 77 K and by a factor of 2 at 300 K. Single-period modulation doped heterostructures have shown enhanced mobility in spite of the relative positions of the Si-doped Al 0.48 In 0.52 As layer and the undoped Ga 0.47 In 0.53 As layer in contrast to the case of GaAs/Al x Ga 1-x As system where mobility enhancement has only been observed for MBE grown Al x Ga 1-x As on top of the undoped GaAs layer.