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

This article investigates the impact of 100 MeV O 7+ and 50 MeV Li 3+ ions on Silicon Photodetectors, focusing on their electrical characteristics with similar S n /S e 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 (R s ) and reverse leakage current (I R ), attributed to ion-induced defects. Oxygen ions showed a monotonic variation in R s , whereas lithium ions exhibited a slight reduction at maximum fluence, possibly due to defect annihilation. Despite differing S e values, 50 MeV Li 3+ ions demonstrated improved device characteristics, suggesting potential defect annihilation. The ratio of S n to S e 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.