| Institution: | 1. School of Mechanical Electronic and Information Engineering, China University of Mining and Technology, Beijing, 100083 P. R. China
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190 P. R. China;2. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190 P. R. China;3. School of Chemistry, Beijing Advanced Innovation Center for Biomedical, Engineering, Beihang University, Beijing, 100191 P. R. China;4. School of Mechanical Electronic and Information Engineering, China University of Mining and Technology, Beijing, 100083 P. R. China |
| Abstract: | Reaching the full potential of solar cells based on photo-absorbers of organic-inorganic hybrid perovskites requires highly efficient charge extraction at the interface between perovskite and charge transporting layer. This demand is generally challenged by the presence of under-coordinated metal or halogen ions, causing surface charge trapping and resultant recombination losses. These problems can be tackled by introducing a small molecule interfacial anchor layer based on dimethylbiguanide (DMBG). Benefitting from interactions between the nitrogen-containing functional groups in DMBG and unsaturated ions in CH3NH3PbI3 perovskites, the electron extraction of TiO2 is dramatically improved in association with reduced Schottky–Read–Hall recombination, as revealed by photoluminescence spectroscopy. As a consequence, the power conversion efficiency of CH3NH3PbI3 solar cells is boosted from 17.14 to 19.1 %, showing appreciably reduced hysteresis. The demonstrated molecular strategy based on DMBG enables one to achieve meliorations on key figures of merit in halide perovskite solar cells with improved stability. |
