Low-cost photoresponsive ITO/Ag-WO3/Ag Schottky diode

Abstract This chapter explores the possibilities of low-cost fabrication and analysis of ITO/Ag-WO3/Ag Schottky diode with turn-on voltage 162 mV, which is significantly less compared with standard silicon-based Schottky diode. The diode is formed using chemically synthesized p-type Ag-WO3 nanocomposite and is found to possess photodetection ability. Also, the role of chemically synthesized Ag-WO3 is investigated as a novel nanocomposite semiconductor candidate for solid-state device fabrication. The diode is fabricated using a dip-coating technique and characterized through current-voltage (I-V), capacitance-voltage (C-V), and impedance spectroscopy techniques. The steep nonlinear behavior of the I-V plot indicated that the current flow mechanism in the Ag-WO3/Ag Schottky junction is based on the thermionic emission theory. A suitable energy level diagram is also explained to show current conduction mechanism in the fabricated diode. Various device parameters like turn-on voltage (162 mV), rectification ratio (219:1), and ideality factor (1.48) are determined through I-V characteristics. Schottky junction parameters like built-in potential (160 mV), carrier concentration (9.56 × 1014 cm− 3), and Schottky barrier height (0.563 eV) are obtained from Mott-Schottky analysis at 10 MHz frequency through C-V characteristics. Equivalent circuit of the device is also analyzed through Impedance analysis at normal conditions. All results are enthusiastic and suggest that the fabricated diode could be used as a rectifier and in radio frequency applications, power supplies, sensors, and detectors. Also, the photoresponsive I-V characteristics with excellent fill factor of 0.99 also suggest its application as a photosensor or detector.