Far-infrared photoconductivity from the shallow donors in n-InP

The wavenumber of the 1s → 2p transition of the shallow donor in n-type InP is found to be 46.3 ± 0.4 cm⁻¹ in zero magnetic field, giving a conduction band effective mass of 0.085 ± 0.005 m₀ and a donor binding energy of 0.00765 eV. The Zeeman splitting of this transition is observed and yields an effective mass of 0.0810 ± 0.0005 m₀. Sharp structure is found in the spectral response of the photoconductivity close to the frequency of the LO phonons. This structure may be related to ‘total negative photoconductivity’.