Electrochemical Fabrication of CdS Nanowire Arrays in Porous Anodic Aluminum Oxide Templates

Abstract

A technique is described for fabricating arrays of uniform CdS nanowires with lengths up to 1 μm and diameters as small as 9 nm by electrochemically depositing the semiconductor directly into the pores of anodic aluminum oxide films from an electrolyte containing Cd2+ and S in dimethyl sulfoxide. The nanowire arrays were characterized by powder X-ray diffraction (XRD) and electron microscopy. The deposited material is found to be hexagonal CdS with the crystallographic c-axis preferentially oriented along the length of the pore. The effects of annealing on the crystallinity of the deposited semiconductor were investigated by XRD and resonance Raman spectroscopy. The deposition technique is, in principle, generalizable as a means of fabricating nanowires of a wide range of semiconductors.

Template electrosynthesis of La(OH)3 and Nd(OH)3 nanowires using porous anodic alumina membranes

“…Comparing our XRD spectra, recorded in a range of 2h values between 10°and 100°, with the ones reported in [12] for hydrothermal synthesized disordered Ln(OH) 3 nanowires, it can be observed the same relative intensity of 100% for the peak (1, 1, 0), and the absence of the peaks (1, 0, 0), (2, 0, 0), (2, 0, 1) for the template electro-synthesized Ln(OH) 3 hydroxides. These findings suggest a slight preferential growth of the Ln(OH) 3 electrodeposited wires along the directions (1, 1, 0) and (0, 0, 2), in agreement with literature where the growth of strongly textured and single-crystal nanowires inside AAMs is often reported [28][29][30]. The polycrystallinity of the Ln(OH) 3 nanowires may be related to the electrodeposition process occurring into pores of wider diameter (about 200 nm).…”

Photoluminescence properties of thermally stable highly crystalline CdS nanoparticles

“…in photonics or recently in quantum computing 1 . Over the past few years, various new routes have been developed to synthesize CdS nanostructures including template assisted synthesis 2 , colloidal micelle 3 , solvothermal method 4 , a method based on nitrilotriacetic acid (N(CH 2 COOH) 3 ) as complex 5 of Cd, carboxyl, and amine terminated PAMAM dendrimers stabilizing agents 6 . All of the above mentioned methods include various complexing and stabilizing agents.…”

Bismuth quantum-wire arrays fabricated by a vacuum melting and pressure injection process

“…Anodic alumina has previously been used to synthesize a variety of metal and semiconductor nanowires, such as Ni, Pd, Au, Pt, and CdS, through chemical or electrochemical processes. [4][5][6][7] However, the diameters of those nanowires have not reached the quantum confinement regime. In order to exhibit strong quantum confinement characteristics, the wire diameter should be smaller than the exciton diameter, which is given by d ex 2eh 2 (m 21 e 1 m 21 h )͞e 2 , where e is the static dielectric constant, and m e and m h are the effective masses of electrons and holes, respectively.…”