Asymmetric ZrSSe Janus monolayers: A first-principles insight into electronic structure and solar cell efficiency

Irfan M.; Huacarpuma B.D.A.; Silva A.M.A.; Ribeiro L.A., Jr; Dias A.C. · Computational Condensed Matter (2026) · DOI: 10.1016/j.cocom.2026.e01478

Resumen

Janus two-dimensional (2D) materials are highly promising for next-generation photovoltaics due to their broken out-of-plane symmetry and excellent optoelectronic properties. This study presents a first-principles investigation of the Janus ZrSSe monolayer using density functional theory (DFT) and the Bethe–Salpeter equation (BSE). The optimized monolayer shows excellent energetic and dynamical stability. Electronic band-structure calculations indicate an indirect semiconducting band gap of 0.58 eV (PBE), which increases to 1.27 eV using the HSE06 functional. Excitonic calculations reveal significant electron–hole coupling, yielding exciton binding energies of 543 meV and 547 meV for indirect and direct transitions, respectively. The material’s linear optical response demonstrates pronounced excitonic effects, leading to enhanced absorption, reflectivity, and refractive index. Crucially, excitonic effects significantly boost solar-energy conversion, resulting in a maximum Shockley–Queisser power conversion efficiency of 31.59%. These findings highlight the strong potential of the Janus ZrSSe monolayer for high-performance ultrathin optoelectronic and photovoltaic devices.

Instituciones: Universidad Nacional de San Agustín de Arequipa