CdSe-Au nanorod networks welded by gold domains - a promising structure for nano-optoelectronic components

TL;DR

This paper reports the synthesis and characterization of CdSe-Au nanorod networks with gold domains, demonstrating their stable conductivity and photoelectrical properties, and how thermal annealing alters their electronic behavior for potential nano-optoelectronic applications.

Contribution

It introduces a colloidal synthesis method for CdSe-Au nanorod networks with gold domains and investigates their electrical and photoelectrical properties, including effects of thermal annealing.

Findings

Networks show stable conductivity insensitive to blue laser light.

Thermal annealing transforms networks to exhibit semiconductor behavior with detectable photocurrent.

Conductivity decreases after annealing but enables photoresponse detection.

Abstract

CdSe-Au networks were synthesized by a colloidal chemistry technique. They entail CdSe nanorods with a diameter of ~10 nm and a length of ~40 nm, which are joined together by Au domains (~5 nm). Individual networks were positioned by AC dielectrophoresis between bow-tie electrodes with a gap of ~100 nm and their conductivity as well as the photoelectrical properties were investigated. Nanorod networks, with multiple Au domains on the nanorod surface, displayed stable conductivity that was not sensitive to blue laser light illumination. Such nanostructures were transformed by thermal annealing to networks with Au domains only at the nanorod tips. In this system the overall conductivity was reduced, but a clear photocurrent signal could be detected, manifesting semiconductor behavior.