Study of the effect of carrier cross-sections, on the leakage current of irradiated silicon detectors, using the exchange charge model

From experimental results during the last few years it is well known that high level of irradiation will cause significant bulk damage, which changes the electrical characteristic of silicon detectors. In addition to increased leakage current, the principle problem to long term operation of these detectors is reverse annealing, which increases the effective doping concentration (Neff) and so the operational voltage. Although Several models have been presented to predict Neff and leakage current in hadron irradiated silicon detectors, only the exchange charge model with non Shockley-Read-Hall (SRH) statistic is satisfactory. From previous works it is evident that electron and hole cross sections of defects that can participate in exchange charge reaction have important effects on electrical properties and especially Neff, but for the most of the defects there is no data or only one of these cross sections is known and usually at points much lower than room temperature. In this paper we used the extrapolated room temperature cross sections of different levels of divacancy (V2) defect and estimated the inter-level cross section of V2 and the electron cross section of E170 defect by means of experimental leakage current data. These extracted cross sections can be used to predict the experimental Neff and may be a new approach for solving some puzzles of hadron irradiated detectors.