title: High Quantum Efficiency Nanopillar Photodiodes Overcoming the Diffraction Limit of Light.
abstract: InAs1-xSbx nanowires have recently attracted interest for infrared sensing applications due to the small bandgap and high thermal conductivity. However, previous reports on nanowire-based infrared sensors required low operating temperatures in order to mitigate the high dark current and have shown poor sensitivities resulting from reduced light coupling efficiency beyond the diffraction limit. Here, InAsSb nanopillar photodiodes with high quantum efficiency are achieved by partially coating the nanopillar with metal that excites localized surface plasmon resonances, leading to quantum efficiencies of ∼29% at 2390 nm. These high quantum efficiency nanopillar photodiodes, with 180 nm diameters and 1000 nm heights, allow operation at temperatures as high as 220 K and exhibit a detection wavelength up to 3000 nm, well beyond the diffraction limit. The InAsSb nanopillars are grown on low cost GaAs (111)B substrates using an InAs buffer layer, making our device architecture a promising path toward low-cost infrared focal plane arrays with high operating temperature.
authors.forename: Wook-Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Pradeep
authors.initials: P
authors.lastname: Senanayake
authors.forename: Alan C
authors.initials: AC
authors.lastname: Farrell
authors.forename: Andrew
authors.initials: A
authors.lastname: Lin
authors.affiliation: Nanopixel Technologies LLC, Los Angeles, California 90095, United States.
authors.forename: Chung-Hong
authors.initials: CH
authors.lastname: Hung
authors.forename: Diana L
authors.initials: DL
authors.lastname: Huffaker
keywords: InAsSb; Nanowires; diffraction limit; nanophotodiode; nanopillar; surface plasmons