A comparative study of optically detected cyclotron resonance in the microwave and far-infrared frequency range in epitaxial InP and GaAs is presented. The electron cyclotron resonances and the inter-impurity 1s-to-2${\mathit{p}}^{+}$ transitions are observed in both high-mobility layers. Cyclotron-resonance-induced impact ionization of shallow donors and bound excitons is the basic mechanism for the observation by photoluminescence.

• Received 30 September 1991

DOI:https://doi.org/10.1103/PhysRevB.45.1504