Current Oscillation and Some Photoelectric Properties in High Resistivity Gallium Arsenide Produced by Irradiation of Fast Neutrons

Abstract

Current oscillation and some photoelectric properties in high resistivity n-type GaAs produced by fast neutron irradiation have been investigated. The spectral response in the photocurrent has a broad peak near the band edge and a relatively high photo-sensitivity still remains at wavelengths longer than the band edge. The photocurrent shows a drastic thermal quenching which begins at about 350°K. In as-irradiated and annealed samples current oscillations caused by traveling high field domain are observed. It is concluded that the current oscillation is due to the field-dependent trapping effect. The current oscillation at room temperature launches even in the dark, while at low temperatures it occurs only under illumination of light. The lower limit of n·l product necessary for leading to the oscillation is estimated as 5×108 cm-2. The oscillation characteristics, especially at low temperatures, are well understood by a simple model.