title: Al nanogrid electrode for ultraviolet detectors.
abstract: Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind.
authors.affiliation: Center for Optical Technologies, Lehigh University, Bethlehem, Pennsylvania 18015, USA. gud208@lehigh.edu
authors.forename: G
authors.initials: G
authors.lastname: Ding
authors.forename: J
authors.initials: J
authors.lastname: Deng
authors.forename: L
authors.initials: L
authors.lastname: Zhou
authors.forename: Q
authors.initials: Q
authors.lastname: Gan
authors.forename: J C M
authors.initials: JC
authors.lastname: Hwang
authors.forename: V
authors.initials: V
authors.lastname: Dierolf
authors.forename: F J
authors.initials: FJ
authors.lastname: Bartoli
authors.forename: C
authors.initials: C
authors.lastname: Mazuir
authors.forename: W V
authors.initials: WV
authors.lastname: Schoenfeld