γ-radiation sensing properties of cerium oxide based thick film structures

Investigations into gamma-radiation-induced changes in the electrical properties of CeO2 thick films of various structures were carried out for dosimetry purposes. The detection of radiation was based on the fact, that properties of the materials undergo changes upon the influence of gamma-radiation. Carbon doping was used to control the resistivity of the CeO2 polymer thick films. Screen-printed capacitors, resistors and pn-junctions were exposed to a disc-type Cs-137 source with an activity of 370 kBq. All devices showed an increase in the values of current with the increase in radiation dose up to a certain level. Capacitors could be recommended for high-dose applications, as they showed consistent changes in conductance and capacitance values with an increase in radiation dose up to 6.12 mSv. Resistors doped with 0.2 wt.% of C showed gradual increase in the values of current with the increase in dose up to 4.42 mSv, whereas resistors with 0.5 wt.% of C sustained a lower dose of 1.7 mSv and were damaged on further exposure. pn-Junctions formed with CeO2 films, printed on single side polished P (100) silicon wafers, exhibited the most sensitivity to gamma-radiation. They showed significant increase in the values of leakage current with the increase in dose up to 0.57 mSv and are therefore suitable for low-dose dosimetry applications. (C) 2004 Elsevier B.V. All rights reserved.