Defining the energy properties of CdI2 film by experimental and theoretical methods

Authors

DOI:

https://doi.org/10.15587/1729-4061.2025.341823

Keywords:

band gap, Urbach energy, absorption spectra, density functional theory

Abstract

This study investigates the compound CdI2, which is actively used as a component in scintillation detectors for the detection of alpha-particle radiation. The research addresses the task to correlate experimental results with theoretically determined parameters of CdI2 films. One of the primary objectives for studying this compound is to determine its electronic structure and optical properties.

The CdI2 thick film was obtained by cleaving from a bulk sample. The average thickness of the CdI2 thick film is 2 μm. The optical properties of CdI2 thick film were investigated by optical absorption spectra. The absorption spectrum fitting method was applied to estimate the optical band gap and Urbach energy of the CdI2 thick film. This method requires only the measurement of the absorbance spectrum, and no additional information, such as the film thickness or reflectance spectra. The optical band gaps and Urbach energy obtained for the CdI2 thick film are 3.05 eV and 5.17 eV, respectively.

Electronic band structure and energy properties were studied for CdI2. We calculated the electron dispersion at high symmetry directions of the Brillouin zone and density of electron estimated with the generalized gradient approximation (GGA). A Perdew–Burke–Ernzerhof functional for solids (PBEsol) was applied. Based on the dispersion of energy bands, the predominant type of conductivity in the studied materials was determined.

Consistency of theoretical and experimental parameters exceeds that reported in previous studies, which supports the use of CdI2 as a model compound, especially in the search and design of novel crystalline materials. The established parameters could be used in the development of components for a scintillation detector

Author Biographies

Mykola Solovyov, Lviv Polytechnic National University

PhD

Department of General Physics

Ihor Semkiv, Lviv Polytechnic National University

PhD

Department of General Physics

Andrii Kashuba, Lviv Polytechnic National University

Doctor of Physical and Mathematical Sciences

Department of General Physics

References

  1. Lavrentyev, A. A., Gabrelian, B. V., Vu, T. V., Ananchenko, L. N., Myronchuk, G. L., Parasyuk, O. V. et al. (2019). Electronic and optical properties of quaternary sulfide Tl2HgSnS4, a promising optoelectronic semiconductor: A combined experimental and theoretical study. Optical Materials, 92, 294–302. https://doi.org/10.1016/j.optmat.2019.04.032
  2. Rudysh, M. Y., Pryshko, I. A., Shchepanskyi, P. A., Stadnyk, V. Y., Brezvin, R. S., Kogut, Z. O. (2022). Optical and electronic parameters of Rb2SO4 crystals. Optik, 269, 169875. https://doi.org/10.1016/j.ijleo.2022.169875
  3. Vu, T. V., Luzhnyi, I. V., Myronchuk, G. L., Bekenev, V. L., Bohdanyuk, M. S., Lavrentyev, A. A. et al. (2021). DFT calculations and experimental studies of the electronic structure and optical properties of Tl4PbI6. Optical Materials, 114, 110982. https://doi.org/10.1016/j.optmat.2021.110982
  4. Rudysh, M. Ya. (2022). Electronic structure, optical and elastic properties of AgAlS2 crystal under hydrostatic pressure. Materials Science in Semiconductor Processing, 148, 106814. https://doi.org/10.1016/j.mssp.2022.106814
  5. Ai, R., Guan, X., Li, J., Yao, K., Chen, P., Zhang, Z., Duan, X., Duan, X. (2017). Growth of Single-Crystalline Cadmium Iodide Nanoplates, CdI2/MoS2 (WS2, WSe2) van der Waals Heterostructures, and Patterned Arrays. ACS Nano, 11 (3), 3413–3419. https://doi.org/10.1021/acsnano.7b01507
  6. Qasrawi, A. F., Hamarsheh, A. A. (2021). Au/CdBr2/SiO2/Au Straddling‐Type Heterojunctions Designed as Microwave Multiband Pass Filters, Negative Capacitance Transistors, and Current Rectifiers. Physica Status Solidi (a), 218 (22). https://doi.org/10.1002/pssa.202100327
  7. Popov, G., Mattinen, M., Hatanpää, T., Vehkamäki, M., Kemell, M., Mizohata, K. et al. (2019). Atomic Layer Deposition of PbI2 Thin Films. Chemistry of Materials, 31 (3), 1101–1109. https://doi.org/10.1021/acs.chemmater.8b04969
  8. Kashuba, A., Zhydachevskyy, Y., Semkiv, I., Franiv, A., Kushnir, O. (2018). Photoluminescence in the solid solution In0.5Tl0.5I. Ukrainian Journal of Physical Optics, 19 (1), 1. https://doi.org/10.3116/16091833/19/1/1/2018
  9. Rybak, O. V. (2024). Thermodynamic Analysis of the Equilibrium Vapor Phase Composition of the Cd-I2 System. Journal of Nano- and Electronic Physics, 16 (1), 01021-1-01021–01024. https://doi.org/10.21272/jnep.16(1).01021
  10. Kaur, H. (2014). Growth and formation of polytypes in crystals of cadmium iodide. Applied Science Research, 6 (1), 64–66. Available at: https://www.scholarsresearchlibrary.com/articles/growth-and-formation-of-polytypes-in-crystals-of-cadmium-iodide.pdf
  11. Bai, X., Jiang, Q., Song, P., Jia, Z.-P., Lu, S., Gao, Z.-K. et al. (2023). Study of electronic and optical properties of CdI2 modulated by electric field: a first-principles study. Optics Express, 31 (19), 31504. https://doi.org/10.1364/oe.497833
  12. Momin, Md. A., Islam, Md. A., Nesa, M., Sharmin, M., Rahman, M. J., Bhuiyan, A. H. (2021). Effect of M (Ni, Cu, Zn) doping on the structural, electronic, optical, and thermal properties of CdI2: DFT based theoretical studies. AIP Advances, 11 (5). https://doi.org/10.1063/5.0050145
  13. Tao, L., Huang, L. (2017). Computational design of enhanced photocatalytic activity of two-dimensional cadmium iodide. RSC Advances, 7 (84), 53653–53657. https://doi.org/10.1039/c7ra09687a
  14. Tyagi, P., Vedeshwar, A. G. (2002). Grain size dependent optical properties of CdI2films. The European Physical Journal Applied Physics, 19 (1), 3–13. https://doi.org/10.1051/epjap:2002043
  15. Kariper, İ. A. (2016). Structural, optical and porosity properties of CdI2 thin film. Journal of Materials Research and Technology, 5 (1), 77–83. https://doi.org/10.1016/j.jmrt.2015.10.005
  16. Tyagi, P., Vedeshwar, A. G., Mehra, N. C. (2001). Thickness dependent optical properties of CdI2 films. Physica B: Condensed Matter, 304 (1-4), 166–174. https://doi.org/10.1016/s0921-4526(01)00392-1
  17. Yan, Z., Yin, K., Yu, Z., Li, X., Li, M., Yuan, Y. et al. (2020). Pressure-induced band-gap closure and metallization in two-dimensional transition metal halide CdI2. Applied Materials Today, 18, 100532. https://doi.org/10.1016/j.apmt.2019.100532
  18. Kunyo, I. M., Kashuba, A. I., Karpa, I. V., Stakhura, V. B., Sveleba, S. A., Katerynchuk, I. M. et al. (2018). The band energy structure of (N(CH3)4)2ZnCl4 crystals. Journal of Physical Studies, 22 (3). https://doi.org/10.30970/jps.22.3301
  19. Perdew, J. P., Ruzsinszky, A., Csonka, G. I., Vydrov, O. A., Scuseria, G. E., Constantin, L. A. et al. (2008). Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces. Physical Review Letters, 100 (13). https://doi.org/10.1103/physrevlett.100.136406
  20. Ilchuk, H., Semkiv, I., Huminilovych, R., Yuryev, S., Rudysh, M., Kashuba, A. (2025). Effect of deposition time on the absorption spectra of CdS nanostructured films. Journal of Physical Studies, 29 (3). https://doi.org/10.30970/jps.29.3702
  21. Ghobadi, N. (2013). Band gap determination using absorption spectrum fitting procedure. International Nano Letters, 3 (1). https://doi.org/10.1186/2228-5326-3-2
  22. Kashuba, A. I. (2023). Influence of metal atom substitution on the electronic and optical properties of solid-state Cd0.75X0.25Te (X= Cu, Ag and Au) solutions. Physics and Chemistry of Solid State, 24 (1), 92–101. https://doi.org/10.15330/pcss.24.1.92-101
Defining the energy properties of CdI2 film by experimental and theoretical methods

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Published

2025-10-30

How to Cite

Solovyov, M., Semkiv, I., & Kashuba, A. (2025). Defining the energy properties of CdI2 film by experimental and theoretical methods. Eastern-European Journal of Enterprise Technologies, 5(12 (137), 19–24. https://doi.org/10.15587/1729-4061.2025.341823

Issue

Vol. 5 No. 12 (137) (2025): Materials Science

Section

Materials Science

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Copyright (c) 2025 Mykola Solovyov, Ihor Semkiv, Andrii Kashuba

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