Multilayer ZnO/Pb/G thin film based extended gate field effect transistor for low dose gamma irradiation detection

Abstract

This study demonstrates the shifts in the threshold voltage ((ΔVTH) of a fabricated extended gate field effect transistor (EGFET) induced by low-dose gamma irradiation as a detection procedure for the collective irradiation dose detection. A metal oxide semiconductor field effect transistor (MOSFET) under ionizing irradiation generates electron–hole (e−-h+) pairs within the oxide layer. These massive holes confined inside the oxide layer owing to their low mobility and produce excess charge. Consequently, the characteristics of the MOSFET and VTH (turn on) are altered, which is detrimental to the transistor’s operation unless inhibited. To resolve this issue, chemical bath deposition was used to grow a multilayer ZnO/Pb/G thin film to assess the feasibility of achieving a low dose gamma (Co-60) irradiation detector. The morphology and structure of the as-prepared film were analyzed using FESEM, XRD, and UV–Vis absorption measurements. The irradiation dose-dependent VTHtraits of the ZnO/Pb/G film-based EGFET were found to be linear. Further, it is established that the simple, rapid, low-cost and eco-friendly technique for the extended gate fabrication may constitute a basis for the development of low doses (up to 12.98 μSv) gamma irradiation dosimetry.