Fir photoconductivity in epitaxial InP

FIR photoconductivity from shallow donors in n-type InP was studied using Fourier transform spectroscopy. The ls → 2p transition frequency was found to be 45.5 ± 0.2 cm⁻¹ in zero magnetic field. Spectral response measurements made in magnetic fields from 0 to 40 kG reveal Zeeman transitions of the ls → 2p (m = 0, ±1) states. Laser magnetospectroscopy was also investigated, employing an optically-pumped FIR laser. There is excellent agreement between the results obtained by the two experiments. From the transition energies, an effective mass of 0.077 ± 0.003 m₀ is obtained. With the experimentally-determined ls → 2p transition energy and the effective mass, the static dielectric constant of InP at 4.2 K was found to be 11.8 ± 0.2.