Design and optimization of a universal, cost-effective gas sensing and photoconductivity measuring system

Abstract

This study details the design, implementation, and validation of a modular, economical instrumentation system for the concurrent assessment of gas-sensing and photoconductivity features in semiconductor materials. The developed platform integrates off-the-shelf components, such as an Arduino-based microcontroller, a high-precision data-logging multimeter, and a time-regulated motorized ball valve, resulting in a cost reduction exceeding 90 % compared to commercial alternatives, while maintaining scientific accuracy. The system includes a bespoke Pyrex glass chamber and a PID-regulated heating element, guaranteeing consistent and replicable environmental conditions for both bulk pellets and thin-film samples. To assess the system's performance, sensing measurements were performed on a CuO pellet subjected to CO₂ gas. Experimental findings indicated a maximum sensitivity of 33.68 % at high temperatures, with response and recovery durations recorded at 692 s and 476 s, respectively. Arrhenius analysis produced activation energies of 0.561 eV in the high-temperature domain and 0.161 eV in the low-temperature domain, demonstrating remarkable quantitative concordance with existing literature. Moreover, the integrated optical module, employing a modulated video projector as a multi-wavelength light source, effectively exhibited the system's ability to conduct photo-induced conductivity measurements. This dual-functional architecture offers a dependable, high-throughput option for researchers investigating intricate light-assisted sensing mechanisms, substantially reducing the financial barrier to advanced materials characterization.