We report on the growth of modulation-doped GaAs/Alx Ga 1-xAs heterostructures with mobilities (μ) on the order of 1×106 cm2 /V s (at 4.2 K) and areal densities (ns) below 8×1010 cm-2. In growing these structures we employ the atomic plane doping technique and ultrathick (>1000 Å) spacer layers. The mobilities of these structures are the highest ever reported for low densities. Measurements of μ vs ns as a function of illumination or gate voltage indicate μ∼ns α behavior with α≃0.6 and, even for ns ≃1.4×1010 cm-2, μ has a value in excess of 0.3×106 cm2 /V s.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)