title: A comprehensive study of sulfonated carbon materials as conductive composites for polymer solar cells.
abstract: Sulfonated carbon nanotubes (S-CNTs) and sulfonated graphene (S-Gra) with superior dispersibility were successfully prepared to modify poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) for applications in polymer solar cells (PSCs). The synergetic effect between S-CNTs/S-Gra and PEDOT:PSS could remove excess insulating PSS chains leading to an obvious phase separation between the PEDOT and PSS chains, which allows the formation of more conductive PEDOT channels. The PEDOT:PSS (Clevios PH 4083):S-CNTs with well-matched work function, favorable morphology, optimized hydrophobicity and superior hole mobility is demonstrated to be an excellent hole transport layer (HTL) for PSCs. However, the PEDOT:PSS (Clevios PH 4083) modified by sulfonated graphene with stacked and wrinkled lamellae as an HTL renders a rough morphology and has a negative impact on the morphology of the active layer, consequently resulting in a poor device performance. Excitingly, PEDOT:PSS (Clevios PH 1000) modified with S-Gra shows high conductivity, because the sulfonated graphene lamellae contribute to the connection between the insulator and conductive PEDOT islands and improves the charge conduction. The PH1000:S-Gra with multiple layers presents excellent electrical conductive properties and a high transmittance (sheet resistance of ∼45 Ω sq(-1) and transmittance of ∼85.5% at 550 nm), which possess great potential for its application as a transparent conductive and flexible electrode in organic electronics.
authors.affiliation: College of Chemistry/Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China. ywchen@ncu.edu.cn.
authors.forename: Ting
authors.initials: T
authors.lastname: Ji
authors.forename: Licheng
authors.initials: L
authors.lastname: Tan
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Hu
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Dai
authors.forename: Yiwang
authors.initials: Y
authors.lastname: Chen