title: Novel cathode interlayers based on neutral alcohol-soluble small molecules with a triphenylamine core featuring polar phosphonate side chains for high-performance polymer light-emitting and photovoltaic devices.
abstract: A new family of neutral alcohol-soluble small molecular materials comprised of electron-rich triphenylamine (TPA) and fluorene featuring phosphonate side chains (FEP) is reported, namely 3TPA-FEP, 2TPA-2FEP and TPA-3FEP, which have different TPA and FEP contents. Due to their good solubility in polar solvents like alcohol, multilayer devices can be fabricated by a wet process from orthogonal solvents. Polymer light-emitting devices with these materials as a cathode interlayer and Al as the cathode show greatly enhanced efficiencies in contrast to control devices without such a cathode interlayer, and their efficiencies are comparable with or even higher than devices with the low work-function metal Ba/Al as the cathode. In addition, high-performance polymer solar cells based on the poly[N-9''-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT):[6,6]-phenyl C71 -butyric acid methyl ester (PC71 BM) system are also achieved with power conversion efficiencies of 7.21%, 6.90% and 6.89%, by utilizing 3TPA-FEP, 2TPA-2FEP and TPA-3FEP as the cathode interlayer, respectively. These efficiencies are also much higher than those for control devices without the cathode interlayer. Although TPA is well-known as a hole-transport unit, the current findings indicate that alcohol-soluble TPA-based small molecules are also a promising cathode interlayer for both electron injection and extraction.
authors: State Key Laboratory of Luminescent Materials and Devices (South China University of Technology) and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China.
authors: Dongcheng
authors: D
authors: Chen
authors: Hu
authors: H
authors: Zhou
authors: Ming
authors: M
authors: Liu
authors: Wei-Ming
authors: WM
authors: Zhao
authors: Shi-Jian
authors: SJ
authors: Su
authors: Yong
authors: Y
authors: Cao
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D000431:Ethanol / Q000737:chemistry*; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D000814:Aniline Compounds; D011108:Polymers; D000431:Ethanol