Gamma radiation sensing properties of NiO thick film pn-junctions

The aim of this work is to develop a novel sensor for gamma radiation with instantaneous dosage readout. Thick films based on nickel oxide (NiO), that are the key sensing element in the proposed approach, were screen-printed on N(111) Si wafers to form pn-junctions. Carbon doping was used to control the conductivity of NiO thick films. All devices were exposed to a disc-type ¹³⁷Cs source with an activity of 370 kBq. The values of radiation damage in pn-junctions were estimated from changes in their current-voltage characteristics. They showed an increase in the values of current with the increase in radiation dose up to certain levels, exceeding these levels results in unstable dosimetric characteristics. Performance parameters of the devices, such as sensitivity to γ-radiation exposure and working dose region, were found to be highly dependent on the composition of the materials used.