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ARTICLE

Halide-Driven Bandgap Engineering and SLME-Based Photovoltaic Performance of Ba₃PX₃ Compounds: A First-Principles Study

Peeyush Kumar Kamlesh^1,*, Himanshi Sharma², Shrikant Verma¹, Ajay Singh Verma^3,4, Reena Saxena⁵, Dinesh C. Sharma⁶

1 Department of Physics, Poornima University, Jaipur, Rajasthan, India
2 School of Basic & Applied Sciences, Nirwan University Jaipur, Jaipur, Rajasthan, India
3 Department of Allied Sciences, Graphic Era Deemed to be University, Dehradun, Uttarakhand, India
4 Department of Physics, University Centre for Research & Development, Chandigarh University, Mohali, Punjab, India
5 School of Applied Sciences, Suresh Gyan Vihar University, Jaipur, Rajasthan, India
6 Department of Physics, Mahatma Jyoti Rao Phoole University, Jaipur, Rajasthan, India

* Corresponding Author: Peeyush Kumar Kamlesh. Email:

Computers, Materials & Continua 2026, 88(2), 23 https://doi.org/10.32604/cmc.2026.081382

Received 01 March 2026; Accepted 28 April 2026; Issue published 15 June 2026

Abstract

In the present work, Ba₃PX₃ (X = F, Cl, Br, I) all-inorganic and lead-free halide compositions have been studied as possible replacements for hybrid perovskites using first-principles calculations. All the considered materials were found to exhibit direct band gaps at the Γ-point, decreasing from 2.37 eV (Ba₃PF₃) to 1.48 eV (Ba₃PI₃). The optical calculations reveal strong absorption in the visible and near-UV regions, with the static dielectric constants ranging from 2.75 to 4.35 in the halide series. All the compounds are mechanically stable and have tuneable ductility and stiffness properties. Lattice stability is confirmed by thermodynamic analysis in broad temperature ranges (0–900 K) and pressure ranges (0–10 GPa). The spectroscopic limit maximum efficiency (SLME), which is a theoretical screening parameter that represents an upper limit, has a value of 39.17% at 300 K for an absorber thickness of 1 μm, comparable to practical thin-film photovoltaic architectures. The findings identify strong trends in the stability of structures, optoelectronic properties, and photovoltaic characteristics within the Ba₃PX₃ family and rank Ba₃PBr₃ and Ba₃PI₃ among the most promising lead-free photovoltaic absorbers.

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