Vertical III-V compound semiconductor nanowires grown on Si(111) surfaces have been attracting interest for
application to opto-electronic integrated circuits (OEICs). In nanowire growth, heterostructures in the axial and radial
direction can be obtained by combining different materials with different growth conditions. These effects should make
it possible to fabricate complicated and functional three-dimensional structures in a bottom-up manner. These advances
should lead to new types of nanodevices. We describe the formation of several heterostructures using GaP-based
nanowires on Si(111). The catalysts used were Au particles obtained from Au colloids. We obtained GaP/GaAs/GaP
nanowires bent at thinned GaAs nodes, InP egg-like structures in GaP nanowires, core-multishell Ga(In)P/GaAs(or air-gap)/
GaP nanowires with flat tops, and GaAs/AlInAs capped GaInAs nanowires for long-wavelength photon emission.
These structures were successively grown on vertical GaP nanowires on Si(111) substrates.