Solution precursor plasma deposition of nanostructured CdS thin films

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2011.12.018· OSTI ID:22212457

Tummala, Raghavender ^[1]; Mohanty, Pravansu S. ^[1]

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1. Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States)

Highlights: Black-Right-Pointing-Pointer Inexpensive process with capability to produce large scale nanostructured coatings. Black-Right-Pointing-Pointer Technique can be employed to spray the coatings on any kind of substrates including polymers. Black-Right-Pointing-Pointer The CdS coatings developed have good electrical conductivity and optical properties. Black-Right-Pointing-Pointer Coatings possess large amount of particulate boundaries and nanostructured grains. -- Abstract: Cadmium sulfide (CdS) films are used in solar cells, sensors and microelectronics. A variety of techniques, such as vapor based techniques, wet chemical methods and spray pyrolysis are frequently employed to develop adherent CdS films. In the present study, rapid deposition of CdS thin films via plasma spray route using a solution precursor was investigated, for the first time. Solution precursor comprising cadmium chloride, thiourea and distilled water was fed into a DC plasma jet via an axial atomizer to create ultrafine droplets for instantaneous and accelerated thermal decomposition in the plasma plume. The resulting molten/semi-molten ultrafine/nanoparticles of CdS eventually propel toward the substrate to form continuous CdS films. The chemistry of the solution precursor was found to be critical in plasma pyrolysis to control the stoichiometry and composition of the films. X-ray diffraction studies confirmed hexagonal {alpha}-CdS structure. Surface morphology and microstructures were investigated to compare with other synthesis techniques in terms of process mechanism and structural features. Transmission electron microscopy studies revealed nanostructures in the atomized particulates. Optical measurements indicated a decreasing transmittance in the visible light with increasing the film thickness and band gap was calculated to be {approx}2.5 eV. The electrical resistivity of the films (0.243 {+-} 0.188 Multiplication-Sign 10{sup 5} {Omega} cm) was comparable with the literature values. These nanostructured polycrystalline CdS films could be useful in sensing and solar applications.

• OSTI ID: 22212457
• Journal Information: Materials Research Bulletin, Vol. 47, Issue 3; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CADMIUM CHLORIDES
COATINGS
DEPOSITION
MICROELECTRONICS
MICROSTRUCTURE
NANOSTRUCTURES
OPTICAL PROPERTIES
PLASMA JETS
POLYCRYSTALS
PRECURSOR
PYROLYSIS
SOLAR CELLS
SOLUTIONS
SUBSTRATES
THIOUREA
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION