Electrical and photoelectrical characteristics of Au/GaN/GaAs Schottky diode

Abstract

The electrical and photovoltaic properties of Au/GaN/GaAs Schottky diode have been investigated in dark conditions and under illumination. The forward and reverse bias current (I–V) measurements were performed at room temperature. The diode has been fabricated in a simple way using nitridation process of GaAs substrate followed by an annealing process at 620°C. The tin (Sn) Ohmic contact, was deposed on the back face of the sample with the use of NH4Cl. The diode has been characterized by I–V measure. The results show that annealed samples with an Ohmic contact has lower values of the series resistance (Rs) and ideality factor n (16.22Ω and 1.92, respectively) compared to the values obtained for the sample without metallization (9.2kΩ, and 5.38). Furthermore, measurement of illumination impact on the device performance has been performed, in the forward bias the superposition principle is reflected in the samples which underwent annealing process. Furthermore some photovoltaic parameters were estimated, such as: short circuits current (ISC), open-circuits voltage (VOC) and fill factor (FF).