Electron-transporting layers in today's stateof-the-art n-i-p organohalide perovskite solar cells are almost exclusively made of metal oxides. Here, we demonstrate a novel mesostructured fullerene-based electron-transporting material (ETM) that is crystalline, hydrophobic, and cross-linked, rendering it solvent-and heat resistant for subsequent perovskite solar cell fabrication The fullerene ETM is shown to enhance the structural and electronic properties of the CH3NH3PbI3 layer grown atop, reducing its Urbach energy from similar to 26 to 21 meV, while also increasing crystallite size and improving texture. The resulting mesostructured n-i-p solar cells achieve reduced recombination, improved device-to-device variation, reduced hysteresis, and a power conversion efficiency above 15%, surpassing the performance of similar devices prepared using mesoporous TiO2 and well above the performance of planar heterojunction devices on amorphous or crystalline [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM). This work is the first demonstration of a viable, hydrophobic, and high-performance mesostructured electron-accepting contact to work effectively in n-i-p perovskite solar cells.
|Original language||English (US)|
|Number of pages||8|
|Journal||ACS Energy Letters|
|State||Published - Oct 27 2016|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the King Abdullah University of Science and Technology, A.H. Balawi and F. Laquai thank K. Vandewal and M. Baier for contributing to the setup for photothermal deflection spectroscopy (PDS). Part of this work was performed at D-line at the Cornell High Energy Synchrotron Source (CHESS) at Cornell University. CHESS is supported by NSF and NIH/NIGMS via NSF Award DMR-1332208. Dr. Detlef-M. Smilgies and Dr. Ruipeng Li from CHESS are thanked for their assistance with beamline setup for the GIWAXS measurements.