Graphitic platform for self-catalysed InAs nanowires growth by molecular beam epitaxy.

Qian D Zhuang,Benjamin J Robinson,Oleg Kolosov,Frazer Anderson,Vladimir Fal’Ko,Tim D Veal,Ana M Sanchez,Mohana K Rajpalke,Ezekiel A Anyebe,Alexander Zhukov

doi:10.1186/1556-276x-9-321

Abstract

We report the self-catalysed growth of InAs nanowires (NWs) on graphite thin films using molecular beam epitaxy via a droplet-assisted technique. Through optimising metal droplets, we obtained vertically aligned InAs NWs with highly uniform diameter along their entire length. In comparison with conventional InAs NWs grown on Si (111), the graphite surface led to significant effects on the NWs geometry grown on it, i.e. larger diameter, shorter length with lower number density, which were ascribed to the absence of dangling bonds on the graphite surface. The axial growth rate of the NWs has a strong dependence on growth time, which increases quickly in the beginning then slows down after the NWs reach a length of approximately 0.8 μm. This is attributed to the combined axial growth contributions from the surface impingement and sidewall impingement together with the desorption of adatoms during the diffusion. The growth of InAs NWs on graphite was proposed following a vapour-solid mechanism. High-resolution transmission electron microscopy reveals that the NW has a mixture of pure zinc-blende and wurtzite insertions.

Highlights

During the last few years, there have been increasing efforts in developing growth of functional hybrid structures of III-V semiconductors on graphene or graphite thin films
Of particular interest are the hybrid structures of InAs NWs on graphite, which may have a number of device applications such as infrared light emitters, photodetectors and thermophotovoltaic electricity generation
InAs NWs have been obtained by molecular beam epitaxy (MBE) on Si [20,21,22], InAs (111)B [23], GaAs (111) [24] and InP (111) [25], InAs NWs on graphene/graphite have only been obtained by metalorganic chemical vapour deposition (MOCVD) [2,3,4,5]

Summary

Introduction

During the last few years, there have been increasing efforts in developing growth of functional hybrid structures of III-V semiconductors on graphene or graphite thin films. In these hybrid structures, the graphene (or graphite) could function as a device electrode owing to its excellent optical transparency, electrical conductivity and flexibility [1]. A few semiconductor materials on graphene have been obtained including nanowires (NWs) of InAs [2,3] and InGaAs [4,5] grown by metalorganic chemical vapour deposition (MOCVD), GaAs [6] NWs grown by molecular beam epitaxy (MBE), ZnO NWs [7,8], as well as thin films such as GaN on graphite substrates via an intermediate ZnO layer [9].

Methods

Results

Conclusion