Interplay of Cation Ordering and Ferroelectricity in Perovskite Tin Iodides: Designing a Polar Halide Perovskite for Photovoltaic Applications

Journal Article · Wed Sep 28 00:00:00 EDT 2016 · Inorganic Chemistry

DOI:https://doi.org/10.1021/acs.inorgchem.6b01701· OSTI ID:1343610

Gou, Gaoyang; Young, Joshua; Liu, Xian; Rondinelli, James M.

Owing to its ideal semiconducting band gap and good carrier transport properties, the fully inorganic perovskite CsSnI₃ has been proposed as a visible-light absorber for photovoltaic (PV) applications. However, compared to the organic inorganic lead halide perovskite CH₃NH₃PbI₃, CsSnI₃ solar cells display very low energy conversion efficiency. In this work, we propose a potential route to improve the PV properties of CsSnI₃. Using first-principles calculations, we examine the crystal structures and electronic properties of CsSnI₃, including its structural polymorphs. Next, we purposefully order Cs and Rb cations on the A site to create the double perovskite (CsRb)Sn₂I₆. We find that a stable ferroelectric polarization arises from the nontrivial coupling between polar displacements and octahedral rotations of the SnI₆ network. These ferroelectric double perovskites are predicted to have energy band gaps and carrier effective masses similar to those of CsSnI₃. More importantly, unlike nonpolar CsSnI₃, the electric polarization present in ferroelectric (CsRb)Sn₂I₆ can effectively separate the photoexcited carriers, leading to novel ferroelectric PV materials with,potentially enhanced energy conversion efficiency.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1343610
• Journal Information: Inorganic Chemistry, Vol. 56, Issue 1; ISSN 0020-1669
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
14 SOLAR ENERGY