Forward-bias operation of Si detectors: a way to work in high-radiation environment

Test diodes irradiated by neutrons with fluences up to 10/sup 15/ cm /sup -2/ were successfully operated as particle detectors under forward bias. The charge collection efficiency (CCE) of ~70as reached for minimum ionising particles at relatively low-bias voltages. The more usual reverse bias requires ~10 times larger voltage to give a similar CCE. A decrease in the charge trapping is observed in forward bias operation compared to that under reverse bias. The dark current under forward bias has the usual temperature dependence. This could be used to optimise the operation condition of forward-biased detectors in a real experiment. (23 refs).