Abstract
The thermally evaporated stoichiometric CdI2 films show goodc-axis alignment normal to substrate plane for film thickness up to 200 nm. The optical absorption data indicate an allowed direct interband transition across a gap of 3.6 eV in confirmation with earlier band structure calculations. However, part of the absorption data near band edge can be fitted to an indirect band gap of 3 eV. The dependence of band gap on film thickness (> 200 nm) can be explained qualitatively in terms of decreasing grain boundary barrier height with grain size.
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Tyagi, P., Vedeshwar, A.G. Grain size dependent optical band gap of CdI2 films. Bull Mater Sci 24, 297–300 (2001). https://doi.org/10.1007/BF02704925
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DOI: https://doi.org/10.1007/BF02704925