Sn-alloying of BaZrS3 chalcogenide perovskite as eco-friendly material for photovoltaics: First principle insight

Abstract

This paper focuses mainly on investigating the effects of partial substitution of Zr cations by Sn cations on the structural, opto-electronic and photovoltaic properties of the chalcogenide perovskite BaZr1−xSnxS3 (x ≤ 0.25). For this purpose, we have used first-principles calculations. Through this approach, we show that the lattice constants and the gap energy (Eg) decrease as the Sn content (x) increases. Furthermore, the Eg values obtained decrease from 1.55 to 0.96 eV. our calculated decomposition energies suggest that it will be difficult to synthesize BaZr1−xSnxS3 alloys for higher Sn contents under thermal equilibrium conditions. Also, the calculated dielectric functions and absorption coefficient show a red shift for higher Sn content. Besides, our theoretical approach, indicate that, the compound BaZr0.815Sn0.125S3 presents a maximum photovoltaic efficiency η of 32.5% for a thickness L = 500 nm, which is close to the Shockley–Queisser limit (33.7%), which makes it a promising candidate for the production of high power conversion efficiency solar cells with ultra-thin absorption layers. sulfide alloys for lead-free perovskite solar cells.