▎ 摘　　要

Vapor-liquid-solid (VLS) growth of freestanding InP nanowires (NWs) on grapheme/Fe is described. In attempting to grow the NWs on graphene/Cu, Ni, and Fe, we found that we were able to grow them only on graphene/Fe, owing to the hard steel formation during the graphene fabrication process. An elemental mapping analysis showed the permeation of phosphorous through the graphene layers, which suggests that small pinholes exist in the layers or at the domain boundaries. TEM results indicate that the NWs grew on graphene without the lattice matching exactly. The low decomposition rate of tertiarybutylphosphine caused In-ball formation on the surface under low-temperature and low-V/III-ratio growth conditions. To reduce the number of In balls and make straight NWs, we alternated one-minute InP growth, which resulted in many freestanding straight InP NWs. We were able to grow these InP NWs on graphene/micron Fe wires, which opens up the possibility of forming flexible optical and electrical devices on various structures in the bottom-up manner. (C) 2014 The Japan Society of Applied Physics