Evaluating the Impact of Dynamic Behavior on the Al/SnO2/p-Si MOS Structures

This study presents a comprehensive numerical analysis of Al/SnO2/p-Si metal–oxide–semiconductor (MOS) structures using the SCAPS-1D simulation framework, with a focus on elucidating the interplay between structural parameters and environmental conditions that govern device performance. By systematically varying the thicknesses of the SnO2 layer and p-Si wafer, as well as simulating temperature-dependent behavior, the investigation reveals in electrical, spectral, and impedance characteristics. Thinner SnO2 films enhance forward bias current and spectral response due to reduced series resistance and increased optical transparency, whereas thicker films effectively suppress leakage currents, preserving rectification behavior. The p-Si wafer thickness is shown to significantly influence near-infrared absorption and carrier collection efficiency, showing its importance in photodetector design. As temperature was elevated from 273 K to 350 K, the results consistently showed a significant enhancement in carrier generation and mobility, leading to a reduction in both the overall impedance and charge transfer resistance. This was evidenced by the systematic decrease in Nyquist semicircle diameter and the leftward shift of C-V curves. The study also confirmed the thermally activated nature of interface states, whose activity was found to be highly sensitive to temperature variations. The findings validate SCAPS-1D as a reliable tool for modeling MOS heterojunctions and provide actionable design principles for optimizing SnO2/p-Si-based optoelectronic devices intended for imaging, sensing, and energy conversion applications.