title: Organic Solar Cells Based on WO2.72 Nanowire Anode Buffer Layer with Enhanced Power Conversion Efficiency and Ambient Stability.
abstract: Tungsten oxide as an alternative to conventional acidic PEDOT:PSS has attracted much attention in organic solar cells (OSCs). However, the vacuum-processed WO3layer and high-temperature sol-gel hydrolyzed WOXare incompatible with large-scale manufacturing of OSCs. Here, we report for the first time that a specific tungsten oxide WO2.72(W18O49) nanowire can function well as the anode buffer layer. The nw-WO2.72film exhibits a high optical transparency. The power conversion efficiency (PCE) of OSCs based on three typical polymer active layers PTB7:PC71BM, PTB7-Th:PC71BM, and PDBT-T1:PC71BM with nw-WO2.72layer were improved significantly from 7.27 to 8.23%, from 8.44 to 9.30%, and from 8.45 to 9.09%, respectively compared to devices with PEDOT:PSS. Moreover, the photovoltaic performance of OSCs based on small molecule p-DTS(FBTTh2)2:PC71BM active layer was also enhanced with the incorporation of nw-WO2.72. The enhanced performance is mainly attributed to the improved short-circuit current density (Jsc), which benefits from the oxygen vacancies and the surface apophyses for better charge extraction. Furthermore, OSCs based on nw-WO2.72show obviously improved ambient stability compared to devices with PEDOT:PSS layer. The results suggest that nw-WO2.72is a promising candidate for the anode buffer layer materials in organic solar cells.
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Longzhen
authors.initials: L
authors.lastname: You
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Fan
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Yunhao
authors.initials: Y
authors.lastname: Cai
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Lin
authors.identifier: http://orcid.org/0000-0002-6070-2384
authors.initials: L
authors.lastname: Guo
authors.affiliation: School of Chemistry and Environment and ‡Heeger Beijing Research and Development Center, Beihang University , Beijing 100191, P. R. China.
authors.forename: Yanming
authors.identifier: http://orcid.org/0000-0001-7839-3199
authors.initials: Y
authors.lastname: Sun
keywords: WO2.72 nanowire; anode buffer layer; efficiency; organic solar cells; stability