Investigation of gamma-irradiation effects on electrical characteristics of Al/(ZnO–PVA)/p-Si Schottky diodes using capacitance and conductance measurements

In this study, Al/(ZnO–PVA)/p-Si (MPS type) Schottky diodes (SDs) were fabricated instead of metal–semiconductor (MS) type SDs with traditional insulator interfacial layer. Additionally, basic electrical parameters of these MPS-type SDs (such as doping acceptor atoms (N_A), depletion layer width (W_D), series resistance (R_s), barrier height (Φ_B), and surface states/traps (N_ss/N_it)) were found as a function of gamma-irradiation by using the capacitance/conductance–voltage (C/G–V) measurements. These measurements under 0–60 kGy radiation doses show that radiation-induced N_ss are more effective in the depletion layer. On the other hand, voltage-dependent profiles of R_s and N_ss were also obtained using Nicollian–Brews and Castagne–Vapaille methods, respectively. Additionally, the C/G–V characteristics were corrected before irradiation and after 60 kGy doses by considering the effects of R_s. These calculations show that R_s is more effective especially in the accumulation region and therefore, it must be considered in the calculations. All these results have indicated that MS-type SDs with (ZnO–PVA) polymer interfacial layer are very sensitive to gamma-irradiation. Hence, they can be successfully used as MPS-type detectors instead of MIS/MOS-type detectors. Hence, they can be successfully used as MPS-type detectors instead of MIS/MOS-type detectors, since polymer layers can be easily grown compared to insulator/oxide layers. Also, they are cheaper, lighter, more flexible, and require low energy consumption. In conclusion, it can be said that although all parameters were affected by gamma-irradiation, no significant defect/deterioration was observed in applied dose range which would hinder the operation of these MPS-type SDs.