First-Principles Investigation of Na₂CuBiCl₆ as a Promising Material for High-Efficiency Optoelectronic Devices

Document Type : Revised File (Highlighted One)

Authors
1 1 Department of Physics, Nigerian Defense Academy, Kaduna, Nigeria
2 2 Department of Physics, Ahmadu Bello University Zaria, Nigeria
3 3 Department of Computer Science, Nigerian Defense Academy, Kaduna, Nigeria
4 4 Department of Science Lab. Tech. Isah Mustapha Agwai 1 Polytechnic, Lafia, Nigeria
Abstract
This research employs first-principles calculations to explore Na₂CuBiCl₆, a double perovskite compound, as a promising material for high-efficiency optoelectronic devices. The structure of Na₂CuBiCl₆ is cubic double perovskite, with Cu⁺ and Bi³⁺ positioned at the B-sites, ensuring stable charge balance and lattice integrity. The Goldschmidt tolerance factor, calculated as 1.008, suggests geometric suitability, and the negative formation enthalpy (ΔH = −0.187 Ry) indicates thermodynamic stability. A Debye temperature of 223.23 K indicates strong lattice dynamics and thermal resilience. An indirect band gap of 1.3 eV is revealed by electronic structure analysis utilising the hybrid Heyd Scuseria Ernzerhof (HSE) functional. This value is consistent with values reported in the literature (1.294 eV), placing the material in the visible light range and making it suitable for optoelectronic applications. Density of states (DOS) analysis has identified orbital contributions indicative of a non-magnetic ground state, which is beneficial for minimizing electronic losses. The optical properties further underscore its potential, showing a strong dielectric function with transitions spanning the visible to ultraviolet regions. The absorption coefficient begins near 3 eV and increases at higher energies. In contrast, the elevated refractive index and extinction coefficient across the visible to near-infrared range suggest efficient light-matter interaction. Overall, Na₂CuBiCl₆ stands out as a structurally stable, thermally robust, and optically active semiconductor, indicating its significant potential for next-generation optoelectronic and thermoelectric applications.
Keywords
Subjects

1.  Yang J, Zhang Z, Wei C, Lu F, Guo Q. Introducing the new generation of Chinese geostationary weather satellites, Fengyun-4. Bulletin of the American Meteorological Society. 2017;98(8):1637-58.
2.  Greul E, Petrus ML, Binek A, Docampo P, Bein T. Highly stable, phase pure Cs 2 AgBiBr 6 double perovskite thin films for optoelectronic applications. Journal of Materials Chemistry A. 2017;5(37):19972-81.
3.  Ji F, Boschloo G, Wang F, Gao F. Challenges and progress in lead‐free halide double perovskite solar cells. Solar Rrl. 2023;7(6):2201112.
4.  Patil HA, More AP. Sustainable solar cells.  Sustainable Electronics: CRC Press; 2025. p. 103-35.
5.  Ayyaz A, Murtaza G, Umer M, Usman A, Raza HH. Structural, elastic, optoelectronic, and transport properties of Na-based halide double perovskites Na2CuMX6 (M= Sb, Bi, and X= Cl, Br) as renewable energy materials: a DFT insight. Journal of Materials Research. 2023;38(20):4609-24.
6.  Baerends EJ. Chemical potential, derivative discontinuity, fractional electrons, jump of the Kohn–Sham potential, atoms as thermodynamic open systems, and other (mis) conceptions of the density functional theory of electrons in molecules. Physical Chemistry Chemical Physics. 2022;24(21):12745-66.
7.  Igbari F, Wang ZK, Liao LS. Progress of lead‐free halide double perovskites. Advanced Energy Materials. 2019;9(12):1803150.
8.  Afraj SN, Velusamy A, Sharma S, Jacob J, Correa-Baena J-P, Chen M-C, et al. Recent progress in molecularly tailored organic hole transporting materials for highly efficient perovskite solar cells. Journal of Materials Chemistry C. 2025;13(30):15234-89.
9.  Creutz SE, Crites EN, De Siena MC, Gamelin DR. Colloidal nanocrystals of lead-free double-perovskite (elpasolite) semiconductors: synthesis and anion exchange to access new materials. Nano letters. 2018;18(2):1118-23.
10. Bartel CJ, Trewartha A, Wang Q, Dunn A, Jain A, Ceder G. A critical examination of compound stability predictions from machine-learned formation energies. npj computational materials. 2020;6(1):97.
11. Jain A, Voznyy O, Sargent EH. High-throughput screening of lead-free perovskite-like materials for optoelectronic applications. The Journal of Physical Chemistry C. 2017;121(13):7183-7.
12. Zelewski S, Urban JM, Surrente A, Maude DK, Kuc A, Schade L, et al. Revealing the nature of photoluminescence emission in the metal-halide double perovskite Cs 2 AgBiBr 6. Journal of Materials Chemistry C. 2019;7(27):8350-6.
13. Shi W, Cai T, Wang Z, Chen O. The effects of monovalent metal cations on the crystal and electronic structures of Cs2MBiCl6 (M= Ag, Cu, Na, K, Rb, and Cs) perovskites. The Journal of Chemical Physics. 2020;153(14).
14. Zhao X-G, Yang J-H, Fu Y, Yang D, Xu Q, Yu L, et al. Design of lead-free inorganic halide perovskites for solar cells via cation-transmutation. Journal of the American Chemical Society. 2017;139(7):2630-8.
15. Shahzad K, Mardare AI, Hassel AW. Accelerating materials discovery: combinatorial synthesis, high-throughput characterization, and computational advances. Science and Technology of Advanced Materials: Methods. 2024;4(1):2292486.
16. Filip MR, Leppert L. Halide perovskites from first principles: from fundamental optoelectronic properties to the impact of structural and chemical heterogeneity. Electronic Structure. 2024;6(3):033002.
17. Meena L, Meena SK, Ahuja U, Heda N, Ahuja B. Electronic properties of EuO and Eu2O3: FP-LAPW and LCAO computations and Compton spectroscopy strategies. Physica Scripta. 2023;98(6):065942.
18. Lawal A, Taura L, Abdullahi YZ, Shaari A, Suleiman AB, Gidado A, et al. Corrections of band gaps and optical spectra of N-doped Sb2Se3 from G0W0 and BSE calculations. Physica B: Condensed Matter. 2022;646:414307.
19. Shahrokhi M, Leonard C. Tuning the band gap and optical spectra of silicon-doped graphene: Many-body effects and excitonic states. Journal of alloys and compounds. 2017;693:1185-96.
20. Murnaghan FD. The compressibility of media under extreme pressures. Proceedings of the National Academy of Sciences. 1944;30(9):244-7.
21. Mir SA, Gupta DC. Analysis of cage structured halide double perovskites Cs2NaMCl6 (M= Ti, V) by spin polarized calculations. Journal of Alloys and Compounds. 2021;854:156000.
22. Al-Qaisi S, Rai D, Haq BU, Ahmed R, Vu TV, Khuili M, et al. First-principles investigation of structural, elastic, thermodynamic, electronic and optical properties of lead-free double perovskites halides: Cs2LiYX6 (X= Br, I). Materials Chemistry and Physics. 2021;258:123945.
23. Al-Qaisi S, Mushtaq M, Alomairy S, Vu TV, Rached H, Haq BU, et al. First-principles investigations of Na2CuMCl6 (M= Bi, Sb) double perovskite semiconductors: materials for green technology. Materials Science in Semiconductor Processing. 2022;150:106947.
24. Mushtaq M, Al-Qaisi S, Lone IUN. Computational study of phase stability, electronic, magnetic and thermoelectric properties of a new quaternary Heusler alloy CrCoIrGa. Solid State Communications. 2022;342:114636.
25. Fedorovskiy AE, Drigo NA, Nazeeruddin MK. The role of Goldschmidt’s tolerance factor in the formation of A2BX6 double halide perovskites and its optimal range. Small Methods. 2020;4(5):1900426.
26. Mahmood Q, Zelai T, Usman T, Al-Qaisi S, Morsi M, Albalawi H, et al. First-principles study of lead-free double perovskites K2Pt (Cl/Br) 6 for optoelectronic and renewable energy applications. Journal of Solid State Chemistry. 2021;301:122294.
27. Aslam M, Aslam A, Sheraz M, Ali B, Ulhassan Z, Najeeb U, et al. Lead toxicity in cereals: Mechanistic insight into toxicity, mode of action, and management. Frontiers in plant science. 2021;11:587785.
28. Al-Qaisi S, Ahmed R, Haq BU, Rai D, Tahir S. A comprehensive first-principles computational study on the physical properties of lutetium aluminum perovskite LuAlO3. Materials Chemistry and Physics. 2020;250:123148.
29. Hassan AuM, Lawal A, Aliyu AM, Kona AM, Abubakar D, Dalhatu SA, et al. Tunable Electronic and Optical Properties of ZnO/Germanene Heterostructure for Solar Cells and Near Infrared Photodetector: A First-Principles Calculations. Applied Sciences, Computing, and Energy. 2025;3(1):134-45.
30. Miao N, Sun Z. Machine learning-enabled optoelectronic material discovery: a comprehensive review. Journal of Materials Informatics. 2025;5(3):N/A-N/A.
31. Penn DR. Wave-number-dependent dielectric function of semiconductors. Physical review. 1962;128(5):2093.