title: Hot electron generation by aluminum oligomers in plasmonic ultraviolet photodetectors.
abstract: We report on an integrated plasmonic ultraviolet (UV) photodetector composed of aluminum Fano-resonant heptamer nanoantennas deposited on a Gallium Nitride (GaN) active layer which is grown on a sapphire substrate to generate significant photocurrent via formation of hot electrons by nanoclusters upon the decay of nonequilibrium plasmons. Using the plasmon hybridization theory and finite-difference time-domain (FDTD) method, it is shown that the generation of hot carriers by metallic clusters illuminated by UV beam leads to a large photocurrent. The induced Fano resonance (FR) minimum across the UV spectrum allows for noticeable enhancement in the absorption of optical power yielding a plasmonic UV photodetector with a high responsivity. It is also shown that varying the thickness of the oxide layer (Al2O3) around the nanodisks (tox) in a heptamer assembly adjusted the generated photocurrent and responsivity. The proposed plasmonic structure opens new horizons for designing and fabricating efficient opto-electronics devices with high gain and responsivity.
authors.forename: Arash
authors.initials: A
authors.lastname: Ahmadivand
authors.forename: Raju
authors.initials: R
authors.lastname: Sinha
authors.forename: Phani Kiran
authors.initials: PK
authors.lastname: Vabbina
authors.forename: Mustafa
authors.initials: M
authors.lastname: Karabiyik
authors.forename: Serkan
authors.initials: S
authors.lastname: Kaya
authors.forename: Nezih
authors.initials: N
authors.lastname: Pala