https://doi.org/10.1140/epjb/s10051-025-01022-0
Research – Computational Methods
Insight into the optoelectronic and thermochemical properties of LiXY2 (X = Ga, Ti; Y = S, Se, Te): a DFT study
1
Department of Chemistry and Biochemistry, Sharda School of Basic Sciences and Research, Sharda University, 201310, Greater Noida, India
2
Department of Mechatronics Engineering, Manipal University Jaipur, Dehmi Kalan, 303007, Jaipur, India
3
SVKM’s NMIMS (Deemed to be University), 400056, Mumbai, India
a prabhat23887@gmail.com, prabhat.ranjan@jaipur.manipal.edu
b tanmoychem@gmail.com, tanmoy.chakraborty@nmims.edu
Received:
1
March
2025
Accepted:
6
August
2025
Published online:
20
August
2025
Structure, optoelectronic, and thermochemical characteristics of Li-based chalcopyrite materials LiXY2 (X = Ga, Ti; Y = S, Se, Te) are studied using DFT approach. Geometry optimization and modeling of LiXY2 are performed using several functionals like B3LYP/LANL2DZ, B3LYP/SDD, B3LYP/DEF2TZVP, CAM-B3LYP/LANL2DZ, CAM-B3LYP/SDD, CAM-B3LYP/DEF2TZVP, APFD/LANL2DZ, APFD/SDD, and APFD/DEF2TZVP within DFT framework and made a comparative analysis. It is found that functional B3LYP/DEF2TZVP provides the most suitable result. Using B3LYP/DEF2TZVP, the HOMO–LUMO gaps of LiGaS2, LiGaSe2 and LiGaTe2 are determined as 3.34, 3.08, and 2.72 eV, respectively, whereas for LiTiS2, LiTiSe2, and LiTiTe2, it is found as 2.71, 2.77, and 1.79 eV correspondingly, signifying their possible uses in optoelectronic devices and solar cells. It also specifies that the replacement of Ga with Ti in the host materials helps in the reduction of the energy gap, which exhibits its better absorption ability. The vertical ionization potential (VIP) as well as vertical electron affinity (VEA) of LiTiY2 are found lesser in magnitude in comparison with LiGaY2. LiTiTe2 exhibits the lowest VIP, whereas LiGaTe2 displays the maximum VEA, which indicates that LiTiTe2 and LiGaTe2 are suitable materials for hole and electron infusion, respectively. LiGaY2 shows a high electronegativity as compared to LiTiY2, which indicates that LiGaY2 offers advantages to enhance electron and hole mobility. The refractive index for LiGaY2 increases from LiGaS2 to LiGaSe2 to LiGaTe2, while for LiTiY2, the highest and the lowest magnitudes are observed for LiTiTe2 and LiTiSe2, respectively. Thermochemical properties of LiXY2 are also computed.
Supplementary Information The online version contains supplementary material available at https://doi.org/10.1140/epjb/s10051-025-01022-0.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

