Growth and characterization of ZnS_xSe_1−xfilms deposited by close-spaced evaporation

Abstract

Polycrystalline thin films of ZnSxSe1−x with x = 0, 0.25, 0.5, 0.75 and 1.0 have been synthesized using close-spaced evaporation. The films were deposited onto glass substrates at different substrate temperatures in the range 200–400 °C. The grown films were characterized using XRD, AFM, EDAX and UV–Vis–NIR spectrophotometer to determine the microstructural properties, composition and optical behaviour. All the ZnSxSe1−x films deposited between 275 and 300 °C were crystallized in cubic structure with a single peak that corresponds to the (1 1 1) plane as the preferred orientation. The composition analysis revealed that the films deposited at Ts = 275–325 °C were nearly stoichiometric. The average surface roughness for ZnSxSe1−x films deposited at 300 °C varied in the range 2–6 nm. The films were highly transparent with optical transmittance >85%. The evaluated energy band gap of the films increased with the increase of sulfur content in the layers and it varied in the range 2.61–3.60 eV. All the layers showed n-type electrical conductivity. The temperature dependence of conductivity was also studied and the activation energy values were evaluated.

Resonant Raman scattering of ZnSxSe1−x solid solutions: the role of S and Se electronic states

“…Until now, a wide range of characterization studies of the ZnSSe thin films have been reported, including structural, electrical and optical properties variations in dependence of the S/Se ratio. 2,5,7,[10][11][12][13][14][15][16] Raman spectroscopy as such has been extensively used for investigating the lattice vibration dynamics in these systems. 12,14,17,18 Raman scattering is a powerful non-destructive method which can provide useful information on the structure, morphology and chemical composition of semiconductor materials, as well as on the photon-electron and electron-phonon interactions occurring in these materials.…”

“…[1][2][3][4] Polycrystalline ZnSSe compounds are excellent candidates for window and/or buffer layers in thin film heterojunction solar cells and promising alternatives to the presently explored materials such as CdS, which contain toxic Cd. 5,6 Additionally, because of its low absorption at infrared wavelength and exciton binding energy, ZnSSe is considered as a future material in the production of biomedical labels, output couplers, lenses, and optically controlled switches. Changing the ratio of S to Se of ZnSSe compounds leads to tuning of the electron affinity and electrical properties which greatly enhances the blue response of the material.…”

Nanostructurred ZnS1-xSex (x =0.4) Thin Film Prepared by Chemical Bath Deposition for Solar cell applications

“…The bulk, single crystal and polycrystalline thin films have been growth and characterized for these applications (Kontos, G.et al,2003;Jung, J. H., et al,2007;Li F., et al,2008;Zhu X. L., et al,2007). Polycrystalline thin films of ZnS1-xSex have been reported for different optoelectronic applications such as blue lasers and blue laser diodes (Patil D. et al,2004), heterojunction nontoxic solar cells (Subbaiah Y., et al,2007;Subbaiah, Y., et al,2008) etc. Now a days, growth and characterization of nanostructure ZnS1-xSex composite thin films have wide scope for optoelectronic device applications.…”