title: Optimization of self-catalyzed InAs Nanowires on flexible graphite for photovoltaic infrared photodetectors.
abstract: The recent discovery of flexible graphene monolayers has triggered extensive research interest for the development of III-V/graphene functional hybrid heterostructures. In order to fully exploit their enormous potential in device applications, it is essential to optimize epitaxial growth for the precise control of nanowire geometry and density. Herein, we present a comprehensive growth study of InAs nanowires on graphitic substrates by molecular beam epitaxy. Vertically well-aligned and thin InAs nanowires with high yield were obtained in a narrow growth temperature window of 420-450 °C within a restricted domain of growth rate and V/III flux ratio. The graphitic substrates enable high nanowire growth rates, which is favourable for cost-effective device fabrication. A relatively low density of defects was observed. We have also demonstrated InAs-NWs/graphite heterojunction devices exhibiting rectifying behaviour. Room temperature photovoltaic response with a cut-off wavelength of 3.4 μm was demonstrated. This elucidates a promising route towards the monolithic integration of InAs nanowires with graphite for flexible and functional hybrid devices.
authors.affiliation: Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Ezekiel A
authors.initials: EA
authors.lastname: Anyebe
authors.affiliation: Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 7ZF, UK.
authors.forename: I
authors.initials: I
authors.lastname: Sandall
authors.affiliation: Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Jin
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZF, UK.
authors.forename: Mohana K
authors.initials: MK
authors.lastname: Rajpalke
authors.affiliation: Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZF, UK.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Veal
authors.affiliation: Key Laboratory of Optoelectronic Chemical Materials and Devices, Jianghan University, Wuhan 430056, China.
authors.forename: Y C
authors.initials: YC
authors.lastname: Cao
authors.affiliation: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: H D
authors.initials: HD
authors.lastname: Li
authors.affiliation: Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: R
authors.initials: R
authors.lastname: Harvey
authors.affiliation: Physics Department, Lancaster University, Lancaster LA1 4YB, UK.
authors.forename: Q D
authors.initials: QD
authors.lastname: Zhuang