Deposition temperature dependence of ZnO nanostructures growth using TCVD for EGFET pH sensor

This work reports on the ability of ZnO nanostructures deposited using thermal chemical vapour deposition (TCVD) method as the sensing membrane for extendend-gate field effect transistor (EGFET) application. Four samples was prepared at different deposition time ranging from 500 to 650 °C in order to study the effect of deposition temperature on EGFET pH sensor performance. The surface morphology of ZnO was examined using FESEM while its ability as EGFET sensing membrane was evaluated using semiconductor device analyzer. From the FESEM results, the ZnO nanostructures varied when the temperature was increased. The best sensitivity of ZnO nanostructures was found at 600 °C with 51.2 mV/pH of sensitivity and 0.9885 of linearity.