Cove‐Edge Nanoribbon Materials for Efficient Inverted Halide Perovskite Solar Cells

• Published in: Angewandte Chemie (International ed.) Vol. 56; no. 46; pp. 14648 - 14652
• Main Authors: Castro, Edison, Sisto, Thomas J., Romero, Elkin L., Liu, Fang, Peurifoy, Samuel R., Wang, Jue, Zhu, Xiaoyang, Nuckolls, Colin, Echegoyen, Luis
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 13.11.2017; Wiley Blackwell (John Wiley & Sons)
• Edition: International ed. in English
• Subjects: Butyric acid; Devices; Electron transport; electron-transporting materials; Energy conversion efficiency; Energy levels; Graphene; Hydrophobicity; Nanoribbons; perovskite; Photoluminescence; Photons; Photovoltaic cells; Solar cells; nanoribbons; perovskite; photoluminescence; electron-transporting materials; solar cells
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201706895

Two cove‐edge graphene nanoribbons hPDI2‐Pyr‐hPDI2 (1) and hPDI3‐Pyr‐hPDI3 (2) are used as efficient electron‐transporting materials (ETMs) in inverted planar perovskite solar cells (PSCs). Devices based on the new graphene nanoribbons exhibit maximum power‐conversion efficiencies (PCEs) of 15.6 % and 16.5 % for 1 and 2, respectively, while a maximum PCE of 14.9 % is achieved with devices based on [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM). The interfacial effects induced by these new materials are studied using photoluminescence (PL), and we find that 1 and 2 act as efficient electron‐extraction materials. Additionally, compared with PC61BM, these new materials are more hydrophobic and have slightly higher LUMO energy levels, thus providing better device performance and higher device stability. Blue (nano)ribbon solar cells: Two electron‐deficient graphene nanoribbons are used as the electron‐transporting materials (ETMs) in inverted perovskite solar cells (PSCs). The nanoribbons provide improved performance over the commonly used PC61BM. The most important benefits are the improved PCE (>10 % over PC61BM) and improved device lifetime owing to the hydrophobic nature of the solubilizing chains on the ribbons.