Photoconductivity spectra and deep levels in the irradiated p+–n–n+ Si detectors

The photoconductivity spectra were investigated in p+–n–n+ Si detectors according to the WODEAN project of CERN-RD50 collaboration. The samples were irradiated by neutrons to the fluence 1×1013–1×1016 cm2. The irradiation created deep levels (DL) below the middle of the band gap that were observed by the extrinsic photoconductivity spectrum. The effective concentration of these levels depended on the fluence and on the isochronal thermal treatment at low temperatures. The DL population changes determined by annealing have been compared with the steady-state lifetime and photoconductivity decay constant.