Open AccessThickness-Dependent Physical Properties of Coevaporated Cu4SnS4 Films
Author(s) -
V. P. Geetha Vani,
M. V. Subba Reddy,
K.T. Ramakrishna Reddy
Publication year - 2013
Publication title -
isrn condensed matter physics
Language(s) - English
Resource type - Journals
eISSN - 2090-7400
pISSN - 2090-7397
DOI - 10.1155/2013/142029
Subject(s) - materials science , orthorhombic crystal system , electrical resistivity and conductivity , raman spectroscopy , band gap , substrate (aquarium) , analytical chemistry (journal) , stoichiometry , transmittance , layer (electronics) , crystallography , crystal structure , optics , composite material , chemistry , optoelectronics , physics , oceanography , organic chemistry , chromatography , geology , electrical engineering , engineering
Cu 4 SnS 4 films of different thicknesses were prepared by thermal coevaporation technique on glass substrates at a constant substrate temperature of 400°C. The layer thickness was varied in the range 0.25–1 μ m. The composition analysis revealed that all the evaporated films were nearly stoichiometric. The XRD patterns indicated the presence of a strong (311) peak as the preferred orientation, following the orthorhombic crystal structure corresponding to Cu 4 SnS 4 films. Raman analysis showed a sharp peak at 317 cm −1 , also related to Cu 4 SnS 4 phase. The optical transmittance spectra suggested that the energy band gap decreased from 1.47 eV to 1.21 eV with increase of film thickness. The hot-probe test revealed that the layers had p-type electrical conductivity. A decrease of electrical resistivity was observed with the rise of film thickness.
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