Reverse annealing studies of irradiated silicon by use of current–voltage measurements

The annealing behaviour of irradiated silicon p-i-n diodes has been investigated by use of I–V measurements. The radiation-induced damage is achieved by the use of 1 MeV neutrons. The results have been analysed and a striking feature is easily noticeable where defects that do not anneal out alter their activity and behave more as generation centres. This means that they are situated in the upper half of the band gap where they act to increase the carrier density and the measured current. The increase in current starts to occur at around 100 days and a change in trap activity at around 180 days after irradiation. The device behaviour, however, remains ohmic throughout indicating that a defect level that is responsible for relaxation behaviour is stable. This study would assist in demonstrating stability of silicon radiation detectors during their operational time.