PIN diode for neutron detection

A PIN diode suitable for use as a neutron dosimeter comprises a strip or wafer of high resistivity silicon with p and n-doped regions on one surface, spaced apart along the strip. The mean carrier lifetime within the high resistivity base region is at least 200 microseconds, while the length of the base region may be more than twice the mean carrier diffusion length. At least the major surfaces of the strip or wafer are oxidised, so minimizing the rate of carrier recombination at the surface. There may be several such doped regions spaced apart along the surface, so forming several PIN diodes of different base lengths and so different neutron sensitivities. (Author)