Analysis of the effect of gamma-ray irradiation and low-temperature characteristics of sol-gel derived ZnO thin-film transistors

Abstract

Introduction: Zinc oxide (ZnO) is a metal-oxide semiconductor with a direct and wide energy band gap of 3.37 eV,

High dose gamma irradiation effects on properties of active layers in ZnO thin film transistors

“…Eventually, the active layer will be sputtered, from within the thin-film, atom by atom. The phenomenon might be optically less noticeable at lower irradiation doses [31]. But, as the surface atoms near the defects become less and less stable, the inverted semi-sputtering rate increases.…”

“…Titanium was deposited as the ohmic contact, passivated by molybdenum and palladium. The rationale behind the S/D metallic structure emerged from the deterioration of titanium/ aluminum contacts in the previous study [31]. The deterioration may come from the lower atomic weight of aluminium, as well as its lower atomic displacement energy (∼16 eV) [34] compared to palladium (∼34 eV) [35] and molybdenum (∼37 eV) [36].…”

“…In a previous report, radiation-hardness of ZnO as active channel layers was investigated after a gamma irradiation dose of 10 MRad [31]. Negligible changes were observed in the peak positions and intensities of photoluminescence (PL) and Raman spectra.…”