title: Designed Quasi-1D Potential Structures Realized in Compositionally Graded InAs1-xPx Nanowires.
abstract: III-V semiconductor heterostructures are important components of many solid-state optoelectronic devices, but the ability to control and tune the electrical and optical properties of these structures in conventional device geometries is fundamentally limited by the bulk dimensionality and the inability to accommodate lattice-mismatched material combinations. Here we demonstrate how semiconductor nanowires may enable the creation of arbitrarily shaped one-dimensional potential structures for new types of designed device functionality. We describe the controlled growth of stepwise compositionally graded InAs1-xPx heterostructures defined along the axes of InAs nanowires, and we show that nanowires with sawtooth-shaped composition profiles behave as near-ideal unipolar diodes with ratchet-like rectification of the electron transport through the nanowires, in excellent agreement with simulations. This new type of designed quasi-1D potential structure represents a significant advance in band gap engineering and may enable fundamental studies of low-dimensional hot-carrier dynamics, in addition to constituting a platform for implementing novel electronic and optoelectronic device concepts.
authors.affiliation: Division of Solid State Physics and NanoLund, Lund University , P.O. Box 118, 221 00 Lund, Sweden.
authors.forename: Gustav
authors.initials: G
authors.lastname: Nylund
authors.affiliation: Division of Solid State Physics and NanoLund, Lund University , P.O. Box 118, 221 00 Lund, Sweden.
authors.forename: Kristian
authors.initials: K
authors.lastname: Storm
authors.affiliation: Division of Solid State Physics and NanoLund, Lund University , P.O. Box 118, 221 00 Lund, Sweden.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lehmann
authors.affiliation: School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
authors.affiliation: Division of Solid State Physics and NanoLund, Lund University , P.O. Box 118, 221 00 Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
keywords: InAs; InP; Semiconductor nanowire; band gap engineering; chemical beam epitaxy; heterostructure