title: Hydrogen-like Wannier-Mott Excitons in Single Crystal of Methylammonium Lead Bromide Perovskite.
abstract: A thorough investigation of exciton properties in bulk CH3NH3PbBr3 perovskite single crystals was carried out by recording the reflectance, steady-state and transient photoluminescence spectra of submicron volumes across the crystal. The study included an examination of the spectra profiles at various temperatures and laser excitation fluencies. The results resolved the first and second hydrogen-like Wannier-Mott exciton transitions at low temperatures, from which the ground-state exciton's binding energy of 15.33 meV and Bohr radius of ∼4.38 nm were derived. Furthermore, the photoluminescence temperature dependence suggested dominance of delayed exciton emission at elevated temperatures, originating from detrapping of carriers from shallow traps or/and from retrapping of electron-hole pairs into exciton states. The study revealed knowledge about several currently controversial issues that have an impact on functionality of perovskite materials in optoelectronic devices.
authors.affiliation: Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute , Technion, Haifa 32000, Israel.
authors.forename: Jenya
authors.initials: J
authors.lastname: Tilchin
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich , Vladimir-Prelog-Weg 1, Zurich CH-8093, Switzerland.|Empa - Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129, Dübendorf CH-8600, Switzerland.
authors.forename: Dmitry N
authors.initials: DN
authors.lastname: Dirin
authors.affiliation: Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute , Technion, Haifa 32000, Israel.
authors.forename: Georgy I
authors.initials: GI
authors.lastname: Maikov
authors.affiliation: Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute , Technion, Haifa 32000, Israel.
authors.forename: Aldona
authors.initials: A
authors.lastname: Sashchiuk
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich , Vladimir-Prelog-Weg 1, Zurich CH-8093, Switzerland.|Empa - Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129, Dübendorf CH-8600, Switzerland.
authors.forename: Maksym V
authors.initials: MV
authors.lastname: Kovalenko
authors.affiliation: Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute , Technion, Haifa 32000, Israel.
authors.forename: Efrat
authors.initials: E
authors.lastname: Lifshitz
keywords: exciton binding energy; hydrogen-like transitions; lead halides; perovskites; photophysics; single crystals