title: Coordination Chemistry Dictates the Structural Defects in Lead Halide Perovskites.
abstract: We show the influence of species present in precursor solution during formation of lead halide perovskite materials on the structural defects of the films. The coordination of lead by competing solvent molecules and iodide ions dictate the type of complexes present in the films. Depending on the processing conditions all PbIS5 (+) , PbI2 S4, PbI3 S3 (-) , PbI4 S2 (2-) , PbI5 S2 (3-) , PbI6 (4-) and 1D (Pb2 I4 )n chains are observed by absorption measurements. Different parameters are studied such as polarity of the solvent, concentration of iodide ions, concentration of solvent molecules and temperature. It is concluded that strongly coordinating solvents will preferentially form species with a low number of iodide ions and less coordinative solvents generate high concentration of PbI6 (-) . We furthermore propose that all these plumbate ions may act as structural defects determining electronic properties of the photovoltaic films.
authors.affiliation: Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló, Spain.|Department of Chemistry, College of Basic science, Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, 18155-144, Tehran, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Rahimnejad
authors.affiliation: Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló, Spain.|Brno University of Technology, Faculty of Chemistry, Materials Research Centre, 612 00, Brno, Czech Republic.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kovalenko
authors.affiliation: Departament de Química Física i Analítica, Universitat Jaume I, 12006, Castelló, Spain.
authors.forename: Sergio Martí
authors.initials: SM
authors.lastname: Forés
authors.affiliation: Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Aranda
authors.affiliation: Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló, Spain. aguerrer@uji.es.
authors.forename: Antonio
authors.identifier: http://orcid.org/0000-0001-8602-1248
authors.initials: A
authors.lastname: Guerrero
keywords: absorption; coordination chemistry; defects; perovskite solar cells; solvent coordination