Electron drift velocity measurement in compositionally graded AlxGa1−xAs by time-resolved optical picosecond reflectivity

Abstract
We have measured for the first time the velocity of minority‐carrier electrons in a heavily doped (p = 2×1018 cm−3) molecular beam epitaxy grown compositionally graded (0.12 eV/μm) AlxGa1−x As layer. The drift velocity is determined to be ve = 2.3×106 cm/s in a quasi‐electric field of 1.2 kV/cm.