Semi-insulating GaAs radiation detectors: PICTS study of neutron-induced defects

Influence of damage by neutrons introduced in semi-insulating GaAs detectors is studied by current-voltage measurement and Photo-Induced Current Transient Spectroscopy (PICTS). Significant rise of the reverse current is observed at neutron fluencies exceeding 10¹³ ncm⁻². The PICTS is used for evaluation of deep-level states in detector structures prior and after neutron bombardment. Formation of a new significant neutron-induced acceptor-like deep level with apparent energy position (EC-Et) 1.02 eV was observed for fluencies >10¹³ ncm⁻².