Fluence dependent carrier lifetime variations in Si detectors determined by photoconductivity and transient grating techniques

Fluence-dependent carrier lifetime variation in heavily proton-irradiated Si detectors has been investigated by the microwave probed photoconductivity (MW-PCD) and transient grating (TG) techniques. Nearly linear decrease of carrier recombination lifetime, from hundreds of ns to few ns, as a function of fluence has been found in Si detectors fabricated on FZ standard and oxygenated material, after irradiation by 24 GeV/c protons with fluence in the range from 1014 to 1015 cm−2. Radiation-defect dependent features of carrier transport and recombination have been analyzed. Models of carrier recombination centers associated with the radiation defects are discussed.