Surface plasmon resonance effects of Ag@ZnO core–shell nanostructure in UV and visible light for photodiode applications

Herein, Ag@ZnO core–shell nanostructures were prepared via the wet chemical method and were then dissolved in methanol and drop cast onto a p–Si wafer. Experimental current–voltage measurements of the Ag@ZnO/p–Si heterojunction device were investigated under both visible and UV illumination of 365 and 395 nm. The photocurrent, responsivity, detectivity, and on/off ratio were found to be dependent on the light intensity of visible light and wavelength of UV light. The low photocurrent at low light intensities and its rapid increase at high light intensities was attributed to the recombination of electrons and holes and also to the presence of traps at low light intensities. The responsivity and detectivity of the photodiode reach 1.32 A/W and 5.47 × 1011 Jones, respectively at 365 nm. On the contrary, the high performance under UV light was explained by the surface plasmon resonance between Ag and ZnO. TEM images of the Ag@ZnO nanoparticles film 3D representation of lightintensity‐dependent I‐V measurements of Ag@ZnO/p‐Si in the visible region