Boosted UV Sensitivity of Er-Doped In2O3 Thin Films Using Plasmonic Ag Nanoparticle-Based Surface Texturing

Abstract

Ag nanoparticles (NPs) were deposited on the sol-gel-processed Erbium-doped Indium Oxide (In2O3:Er) thin films (TFs) using thermal evaporation cum glancing angle deposition technique for the first time. The grazing incidence X-ray diffraction analysis confirms the presence of a face-centered cubic structure of Ag NPs and monoclinic crystal structure of Ag3O4. The presence of Ag NPs on In2O3:Er TFs reduced the photoluminescence emission intensity. Au/In2O3:Er/Si and Au/In2O3:Er/Ag NPs/In2O3:Er/Si (plasmonic) Schottky contact-based detectors were fabricated. Presence of Ag NPs on the In2O3:Er TFs enhanced the photoconduction for the plasmonic detector. The photoresponsivity of the plasmonic device was ∼ 8.7 times greater than In2O3:Er TF-based device for 380 nm wavelength at an applied bias of − 6.6 V. The plasmonic device showed a maximum internal gain of ~ 3181 at 380 nm wavelength. The plasmonic device possessed higher detectivity and lower noise equivalent power as compared to In2O3:Er TF in the ultraviolet (UV) region. The plasmonic device exhibited excellent temporal response with rise and fall time of ~ 0.25 and ~ 0.12 s, respectively. The admirable characteristics of the simple plasmonic device structure can commercially emerge out as UV detector.