MAGNETO-OPTICAL INVESTIGATIONS ON PARA-INSB BICRYSTALS IN THE SUBMILLIMETER WAVELENGTH RANGE

The magneto-optical properties of p-type InSb bicrystals are investigated from lambda equals 57 to 251 mu m at temperatures T less than equivalent to 4. 2 K and magnetic fields up to B equals 6. 5 T. At 118. 8 and 251 mu m the cyclotron resonance of the conduction electrons in the n-inversion layer adjacent to the grain boundary can be detected. At all other wavelengths strong magnetic field dependent absorption effects in the p-type bulk mask the relatively small absorption effects in the inversion layer. The acceptor excitation spectrum of the bulk is discussed. From the periodicity of quantum oscillations three occupied electric subbands are identified. The experimental cyclotron resonance spectra are modeled as the superposition of three cyclotron resonance lines belonging to the three occupied electric subbands. Cyclotron masses are obtained and compared to the experimental data.