RT Journal Article
SR Electronic
T1 Molecular behavior of zero-dimensional perovskites
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP e1701793
DO 10.1126/sciadv.1701793
VO 3
IS 12
A1 Yin, Jun
A1 Maity, Partha
A1 De Bastiani, Michele
A1 Dursun, Ibrahim
A1 Bakr, Osman M.
A1 Brédas, Jean-Luc
A1 Mohammed, Omar F.
YR 2017
UL http://advances.sciencemag.org/content/3/12/e1701793.abstract
AB Low-dimensional perovskites offer a rare opportunity to investigate lattice dynamics and charge carrier behavior in bulk quantum-confined solids, in addition to them being the leading materials in optoelectronic applications. In particular, zero-dimensional (0D) inorganic perovskites of the Cs4PbX6 (X = Cl, Br, or I) kind have crystal structures with isolated lead halide octahedra [PbX6]4− surrounded by Cs+ cations, allowing the 0D crystals to exhibit the intrinsic properties of an individual octahedron. Using both experimental and theoretical approaches, we studied the electronic and optical properties of the prototypical 0D perovskite Cs4PbBr6. Our results underline that this 0D perovskite behaves akin to a molecule, demonstrating low electrical conductivity and mobility as well as large polaron binding energy. Density functional theory calculations and transient absorption measurements of Cs4PbBr6 perovskite films reveal the polaron band absorption and strong polaron localization features of the material. A short polaron lifetime of ~2 ps is observed in femtosecond transient absorption experiments, which can be attributed to the fast lattice relaxation of the octahedra and the weak interactions among them.