title: Organic/Organic Cathode Bi-Interlayers Based on a Water-Soluble Nonconjugated Polymer and an Alcohol-Soluble Conjugated Polymer for High Efficiency Inverted Polymer Solar Cells.
abstract: In this work, organic/organic cathode bi-interlayers based on a water-soluble nonconjugated polymer PDMC and an alcohol-soluble conjugated polymer PFN were introduced to modifythe ITO cathode for inverted polymer solar cells (PSCs). PDMC with ultrahigh molecular weight would facilitate to form strong adsorption on the ITO substrate, while PFN could provide both compatibly interfacial contacts with the bottom PDMC interlayer and the upper organic active layer. The PDMC/PFN cathode bi-interlayers could decrease work function of the ITO cathode to 3.8 eV, supplying the most efficient ohmic interfacial contacts for electron collection at the ITO cathode. With a PTB7:PC71BM blend as the active layer, inverted PSCs based on the PDMC/PFN cathode bi-interlayers showed the highest efficiency of 9.01% and the best air stability within 60 days if compared with devices based on a separate PDMC or PFN cathode interlayer. The results suggest that the PDMC/PFN cathode bi-interlayers would play an important role to achieve high efficiency and stable inverted PSCs.
authors.affiliation: Institute of Polymer Optoelectronic Materials & Devices, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology , Guangzhou 510640, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Cai
authors.affiliation: Institute of Polymer Optoelectronic Materials & Devices, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology , Guangzhou 510640, China.
authors.forename: Hongfu
authors.initials: H
authors.lastname: Jia
authors.affiliation: Institute of Polymer Optoelectronic Materials & Devices, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology , Guangzhou 510640, China.
authors.forename: Junwu
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Polymer Optoelectronic Materials & Devices, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology , Guangzhou 510640, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
keywords: alcohol-soluble conjugated polymer; cathode interlayer; inverted polymer solar cells; lifetime stability; water-soluble nonconjugated polymer