Photoinduced Recharging Phenomena and Vanadium‐Related Centres in GaAs:V

Abstract

Photoinduced recharging phenomena are studied at low temperatures (T < 80 K) on n‐type and semi‐insulating GaAs:V by optical absorption, C‐EPR, and TD‐EPR. Illumination with hv_exc > > 1.05 eV into the photoionization absorption α_II excites electrons into the conduction band and the recharging V + e_ecb → V takes place monitored by optical absorption and EPR. The centre responsible for α_II appears to be a V‐containing complex of unknown structure, rechargable under illumination from (V–X) into (V–X)⁺. The V²⁺(II) centre measured by TD‐EPR is shown to be a second V‐containing complex different from (V–X). The interpretation of all experiments does not require a V‐related mid‐gap level.