Dresden 2017 – wissenschaftliches Programm
CPP 13.9: Poster
Montag, 20. März 2017, 18:30–21:00, P1A
Reduction of Hysteresis through PCBM in Planar Perovskite Solar Cells — •Yu Zhong1, Carlos Andres Melo Luna2, Richard Hildner2, Cheng Li1, and Sven Hüttner1 — 1Organic and Hybrid Electronics, Macromolecular Chemistry I, University of Bayreuth — 2Experimental Physics IV, University of Bayreuth, Germany
Despite the development of organometal perovskite in solar cells, some problems still restrict its large-scale industrial application. Among these questions, it is urgent to address the hysteresis to realize highly efficient and reliable perovskite solar cells (PSC). The hysteresis is the discrepancy between two voltage-sweeping directions when performing a current-voltage (J-V) measurement. To suppress hysteresis, the introduction of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) in the planar PSC has proved as an effective way. However, there is still no comprehensive understanding on it, which is the topic of this poster.
Evidences consistently show that the iodide ion migration is critical for the hysteresis behavior. Herein, we employ PL microscopy to in-situ investigate the ion migration process. By comparing the mobility of the ions in perovskite films with and without PCBM, it shows the decrease of ionic migration velocity when PCBM molecules are involved. Furthermore, temperature-dependent J-V measurements show that the activation energy of iodide ions increases in presence of PCBM molecules. Our experiment suggests that PCBM molecules passivate the iodide related defects and reduce the migration of iodide ions, thus suppressing the hysteretic behavior in PSC.