Thickness Effect on Some Physical Properties of RF Sputtered ZnTe Thin Films for Potential Photovoltaic Applications

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.

An overview on the role of ZnTe as an efficient interface in CdTe thin film solar cells: a review

“…5, 102,[163][164][165][166][167][168][169][170][171] and a leading material for a wide range of potential applications in solid-state electronic devices such as solar cells, green yellow light-emitting diodes, fluorescent screens, interference filters, laser diodes, solar panel displays, integrated circuits, terahertz radiation detectors, switching devices, gamma-ray detectors, nano-sensors, gas sensors, biomedical imaging devices, electroluminescent devices, electromagnetic field coatings, protective coatings, photodetectors, tandem solar cells, and quantum well structures. 103,[172][173][174][175][176][177][178][179][180][181][182] Considering various applications, the discovery of new materials with advanced physical and chemical properties is highly required, and consequently the properties of materials need to be improved. Thus, to achieve better properties, ZnTe thin films can be doped, annealed, and treated after their deposition on various substrates.…”

“…5, 102,163–171 and a leading material for a wide range of potential applications in solid-state electronic devices such as solar cells, green yellow light-emitting diodes, fluorescent screens, interference filters, laser diodes, solar panel displays, integrated circuits, terahertz radiation detectors, switching devices, gamma-ray detectors, nano-sensors, gas sensors, biomedical imaging devices, electroluminescent devices, electromagnetic field coatings, protective coatings, photodetectors, tandem solar cells, and quantum well structures. 103,172–182…”

Studying the effect of copper on the p-ZnTe/n-AgCuInSe2/p-Si for thin films solar cell applications

“…While ZnTe are with wide energy band-gap (2.26-2.4) eV [10,11,12] the crystal structure is Cubic structure chalcopyrite with the lattice constant a = 6.101 Å [13]. AgInSe2 exhibit n-type conductivity [5] Where ZnTe can be used as a p-type conductivity [4,14].…”

FROM Si NANOWIRES TO Ge NANOCRYSTALS FOR VIS-NIR-SWIR SENSORS AND NON-VOLATILE MEMORIES: A REVIEW

“…Group IV semiconductors are intensively investigated [1][2][3][4] along with group III-V [5,6], II-VI [7][8][9][10][11][12][13][14][15][16][17] and IV-VI semiconductors [18,19].…”