Surface-Plasmon-Induced Ag Nanoparticles Decorated In2O3 Nanowires for Low Noise Photodetectors

Abstract

Silver (Ag) nanoparticles (NPs) were synthesized by glancing angle deposition (GLAD) technique on indium oxide (In2O3) nanowires (NWs) over n-type Si substrate. The In2O3 NWs and Ag NPs were morphologically characterized by field emission scanning electron microscopy (FESEM) and electron dispersive spectroscopy (EDS). The complete growth of In2O3 NWs was observed by high-resolution transmission electron microscopy (HRTEM) and corresponding selected area electron diffraction (SAED) pattern was also studied. The structural analysis was done by high-resolution X-ray diffraction (HRXRD), and relevant peaks were identified to calculate the crystalline size. The HRXRD patterns displayed the peak for Ag NPs and monoclinic crystal structure of Ag3O4. The optical properties were analyzed by photoluminescence (PL) emission spectrums. The presence of Ag NPs over In2O3 NWs reduced the PL intensity. Atomic force microscopy (AFM) was also studied to estimate the surface roughness for both the samples. The semi-logarithmic I-V (ln(I)-V) characteristics revealed the enhancement in photoconduction for the n-Si/In2O3 NWs/Ag NPs device at − 4.5 V using a 100-W tungsten filament source. The total ~ 2.6 fold enhancement in photosensitivity were recorded for the n-Si/In2O3 NWs/Ag NPs device at an applied voltage of − 2.4 V. This n-Si/In2O3 NWs/Ag NPs device possessed high detectivity and low noise equivalent power (NEP) as compared with the bare n-Si/In2O3 NWs device.