Simulation & Fabrication of Tungsten Trioxide based photodetectors for opto-electronic applications

Abstract

This work focuses on the design, simulation, and fabrication of a tungsten trioxide (WO₃)-based thin film photodetector for ultraviolet (UV) optoelectronic applications. WO₃ is a promising metal oxide semiconductor due to its wide bandgap, excellent chemical stability, and strong UV absorption characteristics, making it suitable for environmental monitoring, flame detection, and optical sensing applications. The work initially involves modeling and simulation of the WO₃ photodetector using COMSOL Multiphysics to analyze charge transport, optical absorption, and electrical characteristics under UV illumination. Key performance parameters such as responsivity, current–voltage (I–V) behavior, and carrier dynamics are evaluated to optimize device performance. Experimentally, the device fabrication is carried out using a silicon (Si) substrate coated with silicon dioxide (SiO₂), providing electrical insulation and structural stability. A WO₃ thin film is being deposited over the SiO₂ layer to act as the active sensing material. The next phase includes deposition of silver (Ag) electrodes to form efficient metal-semiconductor contacts, followed by ultraviolet (UV) characterization to evaluate photodetection performance, including photocurrent response and sensitivity under UV illumination. The proposed structure aims to achieve a low-cost, CMOS-compatible, and high-sensitivity UV photodetector. The integration of simulation and experimental validation establishes a scalable approach for developing efficient WO₃-based optoelectronic devices suitable for next-generation sensing applications.