The effect of different thicknesses zno nano thin films on Schottky barrier diodes for sensor applications

In this study, various thicknesses of ZnO oxide layer were coated on AuPd/n-GaAs and Ag/n-GaAs metal-semiconductor structures known as Schottky barrier diodes. In addition, it was produced in two groups as AuPd and Ag contacts, and its electrical properties were investigated. ZnO thin films of various thicknesses (25, 50, 100, 175, and 250 nm) were coated on the n-GaAs substrate using the RF sputtering method. Two different Schottky contacts were formed. As the first Schottky contact, AuPd Schottky and ohmic contacts were formed by using DC sputtering method. For the other Schottky contact, Ag contact was formed by dropping silver paste. The thicknesses of the ZnO film were determined by SEM measurements. The current-voltage (I-V) measuments were carried out and Schottky diode performance was investigated. A Labview-based software was developed that analyzes the forward and reverse regions of I-V according to thermionic emission theory, Ohm's law, Cheung and Cheung method, and modified Norde method. Thus, the saturation current (I0), ideality factor (n), potential barrier height (ϕB), series resistance (RS), and shunt resistance (RSH) parameters were calculated. It was observed that 25 nm and 50 nm ZnO coated Schottky diodes performed the best performance.