Comparative Analysis of 50 MeV Li3+ and 100 MeV O7+ Ion Beam Induced Electrical Modifications in Silicon Photodetectors

Abstract

This article investigates the impact of 100 MeV O7+ and 50 MeV Li3+ ions on Silicon Photodetectors, focusing on their electrical characteristics with similar Sn/Se ratios. Elevated ion fluences led to a significant rise in the ideality factor “n”, indicating the presence of Generation-Recombination (G-R) current due to introduced defects, especially those with deep energy levels in the forbidden gap acting as G-R centers. While Ideality factor (n) values decreased for oxygen ions at maximum fluence, they increased for lithium ions, reflecting consistent patterns in series resistance (Rs) and reverse leakage current (IR), attributed to ion-induced defects. Oxygen ions showed a monotonic variation in Rs, whereas lithium ions exhibited a slight reduction at maximum fluence, possibly due to defect annihilation. Despite differing Se values, 50 MeV Li3+ ions demonstrated improved device characteristics, suggesting potential defect annihilation. The ratio of Sn to Se indicated comparable damage contributions from nuclear and electronic energy. Additionally, TRIM computations revealed non-uniform damage distributions, with ions penetrating deep into the substrate, away from the n+/p junction.