title: Facile route to freestanding CH3NH3PbI3 crystals using inverse solubility.
abstract: CH3NH3PbI3 was found to exhibit inverse solubility at high temperatures in γ-butyrolactone. Making use of this unusual, so far unreported phenomenon, we present a facile method for the growth of freestanding crystals of CH3NH3PbI3 from solution without addition of any capping agents or seed particles. Large, strongly faceted crystals could be grown within minutes. This finding may aid in understanding the crystallization process of CH3NH3PbI3 from solution that may lead to improved morphological control of film deposition for a range of device architectures. Our process offers a facile and rapid route to freestanding crystals for use in a broad range of characterization techniques.
authors.affiliation: Laboratory for Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Kadro
authors.affiliation: Laboratory for Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Kazuteru
authors.initials: K
authors.lastname: Nonomura
authors.affiliation: Attolight AG, EPFL Innovation Park, Bâtiment D, CH-1015 Lausanne, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Gachet
authors.affiliation: Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
authors.affiliation: Laboratory for Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt