title: Bias-dependent spectral tuning in InP nanowire-based photodetectors.
abstract: Nanowire array ensembles contacted in a vertical geometry are extensively studied and considered strong candidates for next generations of industrial scale optoelectronics. Key challenges in this development deal with optimization of the doping profile of the nanowires and the interface between nanowires and transparent top contact. Here we report on photodetection characteristics associated with doping profile variations in InP nanowire array photodetectors. Bias-dependent tuning of the spectral shape of the responsivity is observed which is attributed to a Schottky-like contact at the nanowire-ITO interface. Angular dependent responsivity measurements, compared with simulated absorption spectra, support this conclusion. Furthermore, electrical simulations unravel the role of possible self-gating effects in the nanowires induced by the ITO/SiOxwrap-gate geometry. Finally, we discuss possible reasons for the observed low saturation current at large forward biases.
authors.affiliation: Solid State Physics and NanoLund, Lund University, PO Box 118, SE-221 00 Lund, Sweden. Laboratory of Mathematics, Physics and Electrical Engineering, Halmstad University, PO Box 823, SE-301 18 Halmstad, Sweden.
authors.forename: Vishal
authors.initials: V
authors.lastname: Jain
authors.forename: Magnus
authors.initials: M
authors.lastname: Heurlin
authors.forename: Mohammad
authors.initials: M
authors.lastname: Karimi
authors.forename: Laiq
authors.initials: L
authors.lastname: Hussain
authors.forename: Mahtab
authors.initials: M
authors.lastname: Aghaeipour
authors.forename: Ali
authors.initials: A
authors.lastname: Nowzari
authors.forename: Alexander
authors.initials: A
authors.lastname: Berg
authors.forename: Gustav
authors.initials: G
authors.lastname: Nylund
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
authors.forename: Magnus T
authors.initials: MT
authors.lastname: Borgström
authors.forename: Håkan
authors.initials: H
authors.lastname: Pettersson