Novel Ruddlesden–Popper double anti-perovskites Mg4AA′C: first-principles screening and device simulation study for high-efficiency photovoltaic absorbers

Abstract

Developing high-efficiency and environmentally friendly photovoltaic absorbers is crucial for next-generation solar energy technologies. In this work, we propose a novel design strategy that integrates the structural advantages of Ruddlesden–Popper (RP) layered perovskites with the anion-splitting concept in anti-perovskites, enabling the incorporation of the favorable features of both anti-perovskite and double perovskite systems within a unified framework. Based on this strategy, a series of RP-type layered double anti-perovskites, Mg₄AA′C (A = As, Sb, Bi; A′ = Cl, Br, I), were designed and systematically investigated and the resulting compounds exhibit excellent stability and optoelectronic performance. HSE06 hybrid functional calculations with spin–orbit coupling (SOC) indicate that all compounds are direct-bandgap semiconductors. Notably, Mg₄AsBrC exhibits a direct bandgap of 1.35 eV, close to the Shockley–Queisser optimal limit (∼1.34 eV). Carrier mobilities were computed using the Feynman polaron model considering optical phonon scattering. Except for Mg₄SbIC and Mg₄BiIC, all compounds show high electron mobilities (98.69–4205.07 cm² V⁻¹ s⁻¹) and long carrier scattering times (49.20–1195.51 fs), significantly exceeding MAPbI₃ (∼24 cm² V⁻¹ s⁻¹, ∼10 fs). Their visible-light absorption coefficients reach 10⁵ cm⁻¹, comparable to those of MAPbI₃. Power conversion efficiencies (PCEs) estimated via the spectroscopic limited maximum efficiency (SLME) method exceed that of MAPbI₃ (∼30%). Sentaurus TCAD simulations predict a device-level PCE of up to 23.06% with a fill factor of 86.07%, surpassing those of MAPbI₃ (∼17.99%, 79.31%). These results demonstrate that Mg₄AA′C, particularly Mg₄AsBrC, exhibit outstanding optoelectronic properties and strong potential as high-efficiency photovoltaic absorbers.