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Study of the electronic and optical properties of Ba3PCl3 antiperovskite using the DFT/GW-BSE approach
Solar power is the most abundant, free, and sustainable energy source. There is a pressing need to develop next-generation photovoltaics (PVs) that are cheap and highly efficient to harvest the solar energy. A well-studied potential material for such purpose is perovskite with over 24% efficiency reached (Kim et al, 2020). An emerging variant of perovskite is the antiperovskite. It is the inverse of perovskite with a general formula X3BA3 (Tang et al, 2024), where X is an alkaline earth element, B is group 5A pnictogen and A is halogen. Other forms of antiperovskites are double antiperovskites (X6 AA’B2 and X6 BB’A2) (Han et al, 2021). In this work, the newly designed Ba3PCl3 antiperovskite (Tang et al, 2024) was studied for possible application in solar cells. Electronic properties and optical properties of the antiperovskite were computed using density functional theory (DFT-PBE) and GW/Bethe Salpeter (BSE) level of theories as implemented in Quantum Espresso and YAMBO, respectively. DFT-PBE was used to obtain ground state properties such as electron and hole effective masses, and bulk modulus. GW was employed to obtain excitation energies like accurate band gap while BSE was used to compute optical properties and exciton binding energy.
The antiperovskite was found to have a direct band gap with calculated DFT-PBE and GW band gaps as 0.96 and 1.56 eV, respectively. Both real and imaginary dielectric functions of the antiperovskite were computed using Bethe-Salpeter Equation (BSE) level of theory. The dielectric functions were used to obtain different optical properties including absorption spectra, reflectivity, refractive index, etc.
The results obtained show that Ba3PCl3 could be useful for solar cell applications since it has a direct band gap and matches the gap (1-1.8 eV) required for efficient photovoltaic devices. Further investigation of antiperovskites Ba3PCl3 was carried out to know its suitability for photocatalytic water splitting, which is another way of storing solar energy as Hydrogen fuel. One of the conditions for a material to be suitable as photocatalyst for water spiltting is possessing a suitable band gap (1.5-2.4 eV) (Li et al, 2013) - A condition which Ba3PCl3 fulfilled. Other conditions for material suitability for photocatalysis were verified.
References
Tang, G., Liu, X., Wang, S., Hu, T., Feng, C., Zhu, C., ... & Hong, J. (2024). Designing antiperovskite derivatives via atomic-position splitting for photovoltaic applications. Materials Horizons, 11(21), 5320-5330.
Han, D., Feng, C., Du, M. H., Zhang, T., Wang, S., Tang, G., ... & Ebert, H. (2021). Design of high-performance lead-free quaternary antiperovskites for photovoltaics via ion type inversion and anion ordering. Journal of the American Chemical Society, 143(31), 12369-12379.
Kim, J. Y., Lee, J. W., Jung, H. S., Shin, H., & Park, N. G. (2020). High-efficiency perovskite solar cells. Chemical reviews, 120(15), 7867-7918.
Li, Z.; Luo, W.; Zhang, M.; Feng, J.; Zou, Z. Photoelectrochemical cells for solar hydrogen production: Current state of promising photoelectrodes, methods to improve their properties, and outlook. Energy Environ. Sci. 2013, 6, 347–370
| Abstract Category | Materials Physics |
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