CYCLOTRON RESONANCE AND HALL EXPERIMENTS WITH HIGH-PURITY EPITAXIAL GAAS

Cyclotron resonance and cross-modulation experiments at 2 and 1 mm wavelength with an ultra-high purity epitaxial film (ND - NA = 1.3 × 1013 cm-3) of GaAs show that the effective mass at the bottom of the k = 0 conduction band is (0.0648 ± 0.0015)m0 at 11°K with no evidence for any change with temperature in the range from 4 to 115°K. The cyclotron resonance lines sharpen continuously as the temperature is lowered in contrast to the Hall mobility which has a maximum value of about 250,000 cm2/Vs at 50°K. The Hall measurements also show that the activation energy of the shallow donor is 0.0048 ± 0.0002 eV. © 1969.