Abstract:
Studies oii gaiiiiiia radiation ill(lli(ed cilects in electrical and optical properties
of, thin films of metal oxides have been gaining increasing attention, due to their
extensive use in real time garnnia radiation dosimetry. This work aims to study
he electrical and OptiCal properties of metal OXIdeS thin films l.Ifl(ler the influence
of gamma rays by using tliiii films of different metal oxides and their mixtures.
The report describes the variation in various properties of Zinc Oxide, Telluriuni
!)ioxide. and Indium Oxide thin films exposed to gamma radiation using 60Co and
t37Cs sources. The oj)t.ical characterization of the aS-deposite(l thin films as well
as ganima irradiated thin films clearly show that the optical band gap c1ecreases
with increase in the gamma radiation dose up to a certain limit. however, the
ol)tica1 band gap has been fbumal to increase beyond this limit.
* The current-voltage characteristics for the as-(lcposited and gamnmiia irradiated thin
films were analysed to obtain current density versus close l)lOtS at different applied
voltages. The plots obtained clearly show that time current density increases alnmost
liiiearlv with the radiation close up to ccrt:ain limit and this limit is found to be
dependent on thickness of the thin film and rnateria.l to be used. Beyond this limit
the current density is found to decrease. The increase in the current is due to the
lowering of the optical band gap and the decrease iii the current after certain limit
can be attributed to the rising of the optical band gap and the formation of the
clusters.
Studies have also been carried out for time mixture of tellurium dioxide and indium
oxide The observed changes in electrical properties clearly indicate the increase
iii sensitivity for metal oxide mixtures.
