Ahmed, Naser Mahmoud and Rahman, Azhar AbdulAlharbi, Abdullah Marzouq2025-08-102025https://hdl.handle.net/20.500.14154/76102This research enhances the efficiency of UV photodetectors through the synthesis and integration of nanoparticles using laser ablation techniques. The study investigates the effects of bismuth oxide nanosheets (Bi2O3-Nsh), silver nanoparticles (AgNPs), and germanium nanowalls (GeNWs) on ZnO/Si-based UV photodetectors. By change nanoparticle size and shape, the research aims to improve responsivity, sensitivity, and overall performance. Comprehensive characterization of the synthesized nanoparticles and their integration into photodetector architectures was conducted to evaluate their effectiveness and potential for practical applications. Bi2O3 nanosheets (Bi2O3-Nsh) were synthesized using the laser ablation in liquid (LAL) method. The Bi2O3-Nsh were integrated into ZnO/Si photodetectors, and their crystalline structures, morphologies, and optical properties were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and UV-visible spectroscopy analysis. The UV photodetection performance was assessed under 385 nm UV light at varying bias voltages. The ZnO/Bi2O3-Nsh/Si-based UV photodetectors demonstrated a strong response, with the I-V curve showing a significant change from 79 μA to 20 mA at 6 V. Additionally, the device exhibited the highest responsivity of 49.8 A/W, quantum efficiency of 161.61, sensitivity of 25000%, gain of 251, detectivity of 9.86 × 1010 Jones, and a noise equivalent power (NEP) of 1.01 × 10-12 W under 385 nm UV light at a bias voltage of 6 V. These results highlight the potential of Bi2O3-Nsh in enhancing xix ZnO/Si photodetectors. The research also synthesized AgNPs using a cost-effective laser ablation technique combined with RF sputtering. The AgNPs were encapsulated by zinc oxide on a silicon substrate to enhance photodetector efficiency while reducing costs. Three sample configurations (AgNPs/Si, AgNPs/ZnO/Si, and ZnO/AgNPs/Si) were characterized using FESEM, XRD, EDX, and UV-visible spectroscopy. The ZnO/AgNPs/Si photodetector exhibited the highest performance, with a peak responsivity of 132 A/W, quantum efficiency of 429.88, sensitivity of 31400%, gain of 315, detectivity of 18 × 1010 Jones, and an NEP of 0.556 × 10-13 W. These findings underscore the potential of AgNPs in enhancing UV photodetector performance and the feasibility of cost-effective synthesis methods. Furthermore, GeNWs were synthesized via pulsed laser ablation to improve UV photodetection. The GeNWs were integrated into ZnO/Si photodetectors in two configurations: ZnO/GeNWs/Si and GeNWs/ZnO/Si. The ZnO/GeNWs/Si configuration showed impressive performance, with a photocurrent of around 12.8 mA at 6 V, indicating significant enhancement in UV light absorption and carrier charge transport. The device exhibited a responsivity of 31.8 A/W, quantum efficiency of 103.43, sensitivity of 9600%, and detectivity of 4.90 × 1010 Jones. These results demonstrate the potential of GeNWs to enhance UV photodetector performance and the effectiveness of pulsed laser ablation. This research successfully addresses the objectives by using laser ablation techniques to synthesize and integrate Bi2O3-Nsh, AgNPs, and GeNWs into UV photodetectors190enKeywords: UV Photodetectors ZnO/Si Heterojunction Laser Ablation in Liquid (LAL) Bismuth Oxide Nanosheets (Bi₂O₃-Nsh) Silver Nanoparticles (AgNPs) Germanium Nanowalls (GeNWs) Nanostructured PhotodetectorThesis