Theoretical Investigation of the Role of Mixed A(+) Cations in the Structure, Stability, and Electronic Properties of Perovskite Alloys

Author(s)

dos Santos, Ramiro M. ; Ornelas-Cruz, Ivan ; Dias, Alexandre C. ; Lima, Matheus P. ; Da Silva, Juarez L. F.

• Document type: Journal article
• Source: ACS APPLIED ENERGY MATERIALS; v. 6, n. 10, p. 15-pg., 2023-05-11.

Abstract

Experimental studies have demonstrated the importanceof the combinationof different chemical species at the A-, B-, or X-sites in metal-halideABX(3) perovskites to improve the performance of perovskitesolar cells (PSCs). However, from our understanding, further effortsat the atomistic scale are required to unveil the role of alloyingin PSCs. Here, we performed a density functional theory investigationon perovskite alloy materials, namely, Cs( x )MA(1-x )PbI(3), MA( x )FA(1-x )Sn(0.50)Pb(0.50)I(3), and MA( x )FA(1-x )PbBr(2.50)I(0.50) (x = 0.00, 0.25, 0.50, 0.75, 1.00). Equilibriumorthorhombic supercell structures were obtained for all systems withdistorted octahedral environments, in which the magnitude dependson the chemical species. Besides, energetically stable crystals, incomparison with the parent structures, were found only for Cs( x )MA(1-x )PbI(3), even though the remaining alloys presented stronger bonds.Furthermore, we addressed the role of the spin-orbit couplingeffects to the electronic structure, which was critical to estimatethe power conversion efficiency (PCE) with radiative recombinations,e.g., a PCE exceeding 23% was obtained. From our analyses, alloyswith Cs content stood out as the best photovoltaic material. (AU)

• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program