GLAD Synthesized Silver Nanoparticle Patterned CeO2/ITO Vertical Junction UV Photodetector

This work presents the investigation of GLAD technique fabricated silver nanoparticles (Ag NPs) patterned cerium oxide (CeO₂) nanorods on ITO (indium tin oxide) coated glass substrates for use as a UV photodetector. The fabricated samples were studied using numerous techniques such as XRD, FESEM along with EDS, UV-Visible absorption, PL and I-V characterization. The XRD pattern exhibited the polycrystalline nature of cubic fluorite CeO₂ nanorod structure and ITO growing along (111) and (222) directions respectively. The average Ag NP size was found to be ~15.18 nm. FESEM image showed well patterning of Ag NPs on top of the vertically grown CeO₂ nanorods with an average length of 440 nm on 200 nm thick ITO layer. UV-visible spectrum showed strong absorption in the UV region with the fabricated sample giving a direct bandgap of ~3.8 eV. PL spectrum showed a dominant emission at 379 nm due to transfer of charge from the Ce 4f band to the O 2p band. The device revealed good rectifying behavior giving a high photosensitivity of 2050.45 % and responsivity of 10.88 A/W at 4.8 V corresponding to 370 nm wavelength. Moreover, the figure of merits of photodetector such as detectivity, noise equivalent power (NEP) and external quantum efficiency (EQE%) were also investigated.