Temperature dependent band gap in SnS2xSe(2-2x) (x = 0.5) thin films

The research article “Temperature dependent band gap in SnS_2xSe_(2-2x) (x = 0.5) thin films”, co-authored by METU members Prof. Nizami Hasanlı and Prof. Mehmet Parlak , has been published in Materials Science in Semiconductor Processing.

Structural and optical properties of SnS_2xSe_(2-2x) thin films grown by magnetron sputtering method were investigated for composition of x = 0.5 (SnSSe) in the present study. X-ray diffraction, energy dispersive X-ray spectroscopy, atomic force microscopy and scanning electron microscopy methods were used for structural characterization while temperature-dependent transmission measurements carried out at various temperatures in between 10 and 300 K were accomplished for optical investigations. X-ray diffraction pattern of studied composition presented peaks at positions which are between those of SnSe₂ and SnS₂. Transmittance spectra recorded at all applied temperatures were analyzed using well-known Tauc relation. Analyses revealed the direct band gap energy value of SnSSe thin films as 1.75 eV at room temperature. Change of band gap energy as a response to varying temperature were discussed in the study by utilizing Varshni relation. It was shown that variation of gap energy values was well-matched with the Varshni's empirical formula. Energy band gap at absolute zero and rate of change of band gap with temperature were found to be 1.783 eV and −2.1 × 10⁻⁴ eV K⁻¹, respectively.

Delice, S., Isik, M., Gullu, H. H., Terlemezoglu, M., Surucu, O. B., Gasanly, N. M., & Parlak, M. (2020). Temperature dependent band gap in SnS2xSe(2-2x) (x = 0.5) thin films. Materials Science in Semiconductor Processing, 114 doi:10.1016/j.mssp.2020.105083

Article access: https://www.sciencedirect.com/science/article/abs/pii/S1369800119323947?via%3Dihub

Keywords:

Optical properties; SnS₂; SnSe₂; Thin films

Other authors:
Delice, S., Isik, M., Gullu, H.H., Terlemezoglu, M. (METU), & Surucu, O.B.