Investigation of swift heavy ion irradiation effect on Au/CdZnTe/In detector

CdTe crystals grown by Bridgman technique were irradiated with Ag⁷⁺ ion of energy 100 MeV. The current density of 2 to 5 pnA/cm² and fluence 1x10¹³ ions/cm² were used to irradiate the samples. From these results, when 100 MeV Ag⁷⁺ ion passes through the Schottky diode, it was observed that barrier height decreases and ideality factor increases with increase in particle fluences due to creation of defects like vacancies, interstitials, etc. at the interface. Also the gamma spectrum illustrates that the main photo peaks (59.5 keV for ²⁴¹Am and 122 keV for ⁵⁷Co) shift gradually towards the lower channels and there was gradual broadening of peaks as the irradiation fluence increases. All spectroscopic capabilities were lost when the irradiation fluence range exceeds 10¹³ ions.cm⁻² value. Also these higher fluences induce a complete degradation of the transport properties that cannot be overcome for high bias voltage. The observed effects are mainly due to the intense electronic excitation created by fast Ag⁷⁺ ion. The effects of swift heavy ion irradiation on CdZnTe Schottky diode structure based gamma ray detector performance were analyzed.