title: Correlating structure and electronic band-edge properties in organolead halide perovskites nanoparticles.
abstract: After having emerged as primary contenders in the race for highly efficient optoelectronics materials, organolead halide perovskites (OHLP) are now being investigated in the nanoscale regime as promising building blocks with unique properties. For example, unlike their bulk counterpart, quantum dots of OHLP are brightly luminescent, owing to large exciton binding energies that cannot be rationalized solely on the basis of quantum confinement. Here, we establish the direct correlation between the structure and the electronic band-edge properties of CH3NH3PbBr3 nanoparticles. Complementary structural and spectroscopic measurements probing long-range and local order reveal that lattice strain influences the nature of the valence band and modifies the subtle stereochemical activity of the Pb(2+) lone-pair. More generally, this work demonstrates that the stereochemical activity of the lone-pair at the metal site is a specific physicochemical parameter coupled to composition, size and strain, which can be employed to engineer novel functionalities in OHLP nanomaterials.
authors.affiliation: Department of Synchrotron Radiation Instrumentation, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden. tonu.pullerits@chemphys.lu.se and Gas Processing Center, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar.
authors.forename: Kaibo
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden. tonu.pullerits@chemphys.lu.se and Department of Chemistry, Qena Faculty of Science, South Valley University, Qena 83523, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdellah
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Alexander
authors.initials: A
authors.lastname: Generalov
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Dörthe
authors.initials: D
authors.lastname: Haase
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Carlson
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Yuran
authors.initials: Y
authors.lastname: Niu
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Heimdal
authors.affiliation: MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Engdahl
authors.affiliation: Department of Solid State Physics, Lund University, Box 118, 22100, Lund, Sweden.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Messing
authors.affiliation: Department of Chemical Physics, Lund University, Box 124, 22100, Lund, Sweden. tonu.pullerits@chemphys.lu.se.
authors.forename: Tonu
authors.initials: T
authors.lastname: Pullerits
authors.affiliation: IFG Structural Dynamics of (Bio)chemical Systems, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Goettingen, Germany. sophie.canton@desy.de and FS-SCS, Structural Dynamics with Ultra-short Pulsed X-rays, Deutsches Elektronensynchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany.
authors.forename: Sophie E
authors.initials: SE
authors.lastname: Canton