Growth and characterization of GaAs nanowires on carbon nanotubes composite films: toward flexible nanodevices

TL;DR

This study demonstrates the growth of GaAs nanowires on functionalized carbon nanotube films, creating a hybrid material with potential for flexible optoelectronic devices such as solar cells and sensors.

Contribution

It introduces a novel method for growing GaAs nanowires on carbon nanotube films, enabling flexible nanodevices with high optical quality and electrical functionality.

Findings

Dense GaAs nanowire growth on nanotube films

High optical quality of individual nanowires

Rectifying current-voltage behavior indicating pn-junctions

Abstract

Poly(ethylene imine) functionalized carbon nanotube thin films, prepared using the vacuum filtration method, were decorated with Au nanoparticles by in situ reduction of HAuCl4 under mild conditions. These Au nanoparticles were subsequently employed for the growth of GaAs nanowires (NWs) by the vapor-liquid-solid process in a gas source molecular beam epitaxy system. The process resulted in the dense growth of GaAs NWs across the entire surface of the single-walled nanotube (SWNT) films. The NWs, which were orientated in a variety of angles with respect to the SWNT films, ranged in diameter between 20 to 200 nm, with heights up to 2.5 um. Transmission electron microscopy analysis of the NW-SWNT interface indicated that NW growth was initiated upon the surface of the nanotube composite films. Photoluminescence characterization of a single NW specimen showed high optical quality. Rectifying asymmetric current-voltage behavior was observed from contacted NW ensembles and attributed to the core-shell pn-junction within the NWs. Potential applications of such novel hybrid architectures include flexible solar cells, displays, and sensors.