title: Adjustable optical response of amorphous silicon nanowires integrated with thin films.
abstract: We experimentally demonstrate a new optical platform by integrating hydrogenated amorphous silicon nanowire arrays with thin films deposited on transparent substrates like glass. A 535 nm thick thin film is anisotropically etched to fabricate vertical nanowire arrays of 100 nm diameter arranged in a square lattice. Adjusting the nanowire length, and consequently the thin film thickness permits the optical properties of this configuration to be tuned for either transmission filter response or enhanced broadband absorption. Vivid structural colors are also achieved in reflection and transmission. The optical properties of the platform are investigated for three different etch depths. Transmission filter response is achieved for a configuration with nanowires on glass without any thin film. Alternatively, integrating thin film with nanowires increases the absorption efficiency by ∼97% compared to the thin film starting layer and by ∼78% over nanowires on glass. The ability to tune the optical response of this material in this fashion makes it a promising platform for high performance photovoltaics, photodetectors and sensors.
authors.affiliation: Department of Electrical and Computer Engineering, University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada. Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada.
authors.forename: Navneet
authors.initials: N
authors.lastname: Dhindsa
authors.forename: Jaspreet
authors.initials: J
authors.lastname: Walia
authors.forename: Minoli
authors.initials: M
authors.lastname: Pathirane
authors.forename: Iman
authors.initials: I
authors.lastname: Khodadad
authors.forename: William S
authors.initials: WS
authors.lastname: Wong
authors.forename: Simarjeet Singh
authors.initials: SS
authors.lastname: Saini