title: Identification and characterization of the intermediate phase in hybrid organic-inorganic MAPbI3 perovskite.
abstract: Perovskite films were prepared using single step solution deposition at different annealing temperatures and annealing times. The crystal structure, phases and grain size were investigated with XRD, XPS and SEM/EDX. The prepared films show a typical orientation of tetragonal perovskite phase and a gradual transition at room temperature from the yellow intermediate phase to the black perovskite phase. Films with high purity were obtained by sintering at 100 °C. In addition, the chemical composition and crystal structure of intermediate phase were investigated in detail. FTIR, UV-vis and NMR spectra revealed the occurance of DMF complexes. Interestingly, the intermediate phase could be transformed to the black perovskite phase upon X-ray irradiation. In addition, the recovery of the aged perovskite films from a yellow intermediate phase back to the black perovskite was shown to be viable via heating and X-ray irradiation.
authors.affiliation: Department of Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. burda@case.edu and Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. anna.samia@case.edu.
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. anna.samia@case.edu.
authors.forename: Christopher
authors.initials: C
authors.lastname: McCleese
authors.affiliation: Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. anna.samia@case.edu.
authors.forename: Charles
authors.initials: C
authors.lastname: Kolodziej
authors.affiliation: Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. anna.samia@case.edu.
authors.forename: Anna C S
authors.initials: AC
authors.lastname: Samia
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China. yixin.zhao@sjtu.edu.cn.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. burda@case.edu and Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. anna.samia@case.edu.
authors.forename: Clemens
authors.initials: C
authors.lastname: Burda