title: Morphology Engineering: A Route to Highly Reproducible and High Efficiency Perovskite Solar Cells.
abstract: Despite the rapid increase in the performance of perovskite solar cells (PSC), they still suffer from low lab-to-lab or people-to-people reproducibility. Aiming for a universal condition to high-performance devices, we investigated the morphology evolution of a composite perovskite by tuning annealing temperature and precursor concentration of the perovskite film. Here, we introduce thermal annealing as a powerful tool to generate a well-controlled excess of PbI2in the perovskite formulation and show that this benefits the photovoltaic performance. We demonstrated the correlation between the film microstructure and electronic property and device performance. An optimized average grain size/thickness aspect ratio of the perovskite crystallite is identified, which brings about a highly reproducible power conversion efficiency (PCE) of 19.5 %, with a certified value of 19.08 %. Negligible hysteresis and outstanding morphology stability are observed with these devices. These findings lay the foundation for further boosting the PCE of PSC and can be very instructive for fabrication of high-quality perovskite films for a variety of applications, such as light-emitting diodes, field-effect transistors, and photodetectors.
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Dongqin
authors.initials: D
authors.lastname: Bi
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Jingshan
authors.initials: J
authors.lastname: Luo
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.|School of Chemical Engineering and Technology, Tianjin University, 300072, Tianjin, P. R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Magrez
authors.affiliation: Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Evangelia Nefeli
authors.initials: EN
authors.lastname: Athanasopoulou
authors.affiliation: Laboratory of Photomolecular Science, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D011211:Electric Power Supplies; D004738:Engineering; D010087:Oxides / Q000737:chemistry*; D012993:Solar Energy; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014173:Transistors, Electronic
chemical_list: D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; D014025:Titanium
keywords: lead iodide; morphology; perovskites; solar cells; stability