title: Improved morphology control using a modified two-step method for efficient perovskite solar cells.
abstract: A two-step wet chemical synthesis method for methylammonium lead(II) triiodide (CH3NH3PbI3) perovskite is further developed for the preparation of highly reproducible solar cells, with the following structure: fluorine-doped tin oxide (FTO)/TiO2 (compact)/TiO2 (mesoporous)/CH3NH3PbI3/spiro-OMeTAD/Ag. The morphology of the perovskite layer could be controlled by careful variation of the processing conditions. Specifically, by modifying the drying process and inclusion of a dichloromethane treatment, more uniform films could be prepared, with longer emission lifetime in the perovskite material and longer electron lifetime in solar cell devices, as well as faster electron transport and enhanced charge collection at the selective contacts. Solar cell efficiencies up to 13.5% were obtained.
authors.affiliation: Department of Chemistry-Ångström Laboratory, Uppsala University , Box 532, SE 751 20 Uppsala, Sweden.
authors.forename: Dongqin
authors.initials: D
authors.lastname: Bi
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: El-Zohry
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.forename: Gerrit
authors.initials: G
authors.lastname: Boschloo
keywords: dichloromethane; emission lifetime; mesoporous TiO2; methylammonium lead(ii) triiodide; photovoltaic; solution-processed semiconductor