Abstract
Zinc telluride thin films with different thicknesses were grown onto glass substrates by the rf magnetron sputtering technique, using time as a variable growth parameter. All other deposition process parameters were kept constant. The deposited thin films with thickness from 75 to 460 nm were characterized using X-ray diffraction, electron microscopy, atomic force microscopy, ellipsometry, and UV-Vis spectroscopy, to evaluate their structures, surface morphology, topology, and optical properties. It was found out that the deposition time increase leads to a larger growth rate. This determines significant changes on the ZnTe thin film structures and their surface morphology. Characteristic surface metrology parameter values varied, and the surface texture evolved with the thickness increase. Optical bandgap energy values slightly decreased as the thickness increased, while the mean grains radius remained almost constant at ~9 nm, and the surface to volume ratio of the films decreased by two orders of magnitude. This study is the first (to our knowledge) that thoroughly considered the correlation of film thickness with ZnTe structuring and surface morphology characteristic parameters. It adds value to the existing knowledge regarding ZnTe thin film fabrication, for various applications in electronic and optoelectronic devices, including photovoltaics.
Highlights
There is a need for new nanostructured materials with enhanced properties, due to the development of new systems and materials that use nanotechnologies
Due to characteristics obtained at the time of the deposition process such as: low resistivity, high transparency in the visible spectrum, etc. [1–4], thin layers of zinc telluride (ZnTe) are used in various modern technologies, which are implemented in various micro- and nanostructured devices, such as light emitting diodes, solar cells, photodetectors, etc. [1–18]
Using the scanning electron microscopy (SEM) analyses options, the local thickness of the ZnTe layers deposited by rf magnetron sputtering vas estimated
Summary
There is a need for new nanostructured materials with enhanced properties, due to the development of new systems and materials that use nanotechnologies. ZnTe is a sensitive material in the green spectral region, with a bandgap of 2.26 eV and a low electronic affinity of 3.53 eV; it can be used as a p-type buffer material in hetero-junction solar cells based on CdTe [10–13,18]. It can be used as back contact material to CdTe-based solar cells [14] in a multilayer device. It is a precious material from an ecological point of view; it can be used as a replacement for the CdS
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have