title: Optical control of internal electric fields in band gap-graded InGaN nanowires.
abstract: InGaN nanowires are suitable building blocks for many future optoelectronic devices. We show that a linear grading of the indium content along the nanowire axis from GaN to InN introduces an internal electric field evoking a photocurrent. Consistent with quantitative band structure simulations we observe a sign change in the measured photocurrent as a function of photon flux. This negative differential photocurrent opens the path to a new type of nanowire-based photodetector. We demonstrate that the photocurrent response of the nanowires is as fast as 1.5 ps.
authors.affiliation: Walter Schottky Institut and Physik-Department, Technische Universität München , D-85748 Garching, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Erhard
authors.forename: A T M Golam
authors.initials: AT
authors.lastname: Sarwar
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.forename: D W
authors.initials: DW
authors.lastname: McComb
authors.forename: R C
authors.initials: RC
authors.lastname: Myers
authors.forename: A W
authors.initials: AW
authors.lastname: Holleitner
keywords: InGaN nanowire; band structure; photodetector; ultrafast photocurrent