INVESTIGATION OF MSM UV PHOTODETECTOR BASED ON PLASMONIC EFFECT OF METALS NANOPARTICLE DECORATED POROUS SILICON

Abstract

Photodetectors (PDs) are essential in ultraviolet (UV) sensing, biomedical diagnostics, environmental monitoring, and optical communication; however, conventional silicon-based devices suffer from poor UV sensitivity and surface recombination defects. Porous silicon (PS) provides a promising platform due to its high surface area and strong light-trapping capability, while integrating metallic nanoparticles (NPs) can induce surface plasmon resonance (SPR) to enhance light absorption and charge carrier generation. This study investigates and compares the plasmonic effects of Ag, Au, Cu, and Ni nanoparticles on PS-based PDs to improve UV detection efficiency. PS was fabricated using photoelectrochemical etching (PECE), while NPs were synthesized by pulsed laser ablation in liquid (PLAL) and deposited on PS using drop-casting. We performed electrical (I–V and I–T) measurements under dark and UV conditions, along with FESEM, XRD, and UV-Vis NIR analyses. The Au NPs/PS device achieved the highest sensitivity (37,465%) with rise and decay times of 0.232 s and 0.20 s, respectively, because of Au's chemical inertness, while Cu NPs/PS showed the lowest sensitivity (640%) with rise and decay times of 0.321 s and 0.22 s, respectively, due to Cu's high oxidation tendency. These results demonstrate the critical role of nanoparticle material selection in enhancing PS based PDs and underline their potential applications in UV sensing, secure optical communication, flame detection, and space exploration. This work provides a clear pathway for developing high-performance plasmon-enhanced PDs with improvez sensitivity, stability, and applicability.