Optical properties of ZnO deposited by atomic layer deposition (ALD) on Si nanowires
International audience; In this work, we report proof-of-concept results on the synthesis of Si core/ ZnO shell nanowires (SiNWs/ZnO) by combining nanosphere lithography (NSL), metal assisted chemical etching (MACE) and atomic layer deposition (ALD). The structural properties of the SiNWs/ZnO nanostructures prepared were investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies. The X-ray diffraction analysis revealed that all samples have a hexagonal wurtzite structure. The grain sizes are found to be in the range of 7-14 nm. The optical properties of the samples were investigated using reflectance and photoluminescence spectroscopy. The study o…
Visible Photoluminescence of Variable-Length Zinc Oxide Nanorods Embedded in Porous Anodic Alumina Template for Biosensor Applications
Zinc oxide (ZnO) and porous anodic aluminum oxide (PAAO) are technologically important materials, rich with features that are of interest in optical applications, for example, in light-emitting and sensing devices. Here, we present synthesis method of aligned ZnO nanorods (NR) with 40 nm diameter and variable length in 150 to 500 nm range obtained by atomic layer deposition (ALD) of ZnO in pores of continuously variable thickness PAAO. The relative intensity of yellow (1.99 eV), green (2.35 eV), and blue (2.82 eV) photoluminescence (PL) components originating from the different types of defects, varied with non-monotonic dependency on the composite film thickness with a Fabry–Pérot like mod…
Improved Crystalline Structure and Enhanced Photoluminescence of ZnO Nanolayers in Bi2Se3/ZnO Heterostructures
The Bi2Se3/ZnO heterostructure is a new combination of high- and low-band-gap nanomaterials that can be implemented for optoelectronic devices. The influence of the Bi2Se3 substrate on crystallizat...
Photoluminescence Study of Defects in ZnO-Coated Polyacrylonitrile Nanofibers
International audience; Core-shell nanostructures of one-dimensional (1D) polyacrylonitrile (PAN)/zinc oxide (ZnO) were obtained by combining atomic layer deposition (ALD) and electrospinning. Nanofibers with different ZnO thicknesses were synthesized and investigated. The present work offers novel information about 1D ZnO structural defects and activation energies (Ea) by performing photoluminescence (PL) measurements. PL measurements of 1D ZnO/PAN samples were investigated from 77 K to 273 K (room temperature). By analyzing the obtained data of the emission spectrum, Ea and temperature coefficients were calculated. The results let us suggest an approximate model of defects in 1D ZnO/PAN s…