title: Interface-induced crystalline ordering and favorable morphology for efficient annealing-free poly(3-hexylthiophene): fullerene derivative solar cells.
abstract: A simple approach to fabricate high-efficiency annealing-free poly(3-hexylthiophene): [6,6]-phenyl C(61)-butyric acid methyl ester (P3HT:PCBM) solar cells is reported by using p-type CuI to substitute PEDOT:PSS as anode buffer layer. It is found that the P3HT:PCBM blend films deposited on CuI surface show different orientation of crystalline P3HT domains and phase separation from those deposited on PEDOT:PSS surface. A nanoscale phase separation of P3HT and PCBM with domain sizes about 10-30 nm is formed for the P3HT:PCBM blend films deposited on CuI surface. Absorption and grazing incidence X-ray diffraction (GIXRD) experiments indicate that the CuI layer not only induces the self-organization of P3HT chains into well-ordered structure but also results in the vertical orientation of π-π stacking planes of P3HT with respect to the substrate which is favorable for the hole collection in polymer solar cells. Hole-transport investigation discloses that hole mobility of the as-spincast P3HT:PCBM blend film on CuI surface is increased with 3 orders of magnitude compared to the P3HT:PCBM film deposited on PEDOT:PSS. A power conversion efficiency of 3.1% for the as-spincast P3HT:PCBM solar cell with CuI buffer layer is about 4-fold enhancement compared to 0.83% of the control device with PEDOT:PSS, and is comparable to the reported P3HT:PCBM solar cells subjected to post thermal treatments. This work implies that interfacial engineering is a promising approach for manipulating morphology of active layer and can potentially simplify the process and shorten the fabrication time of polymer solar cells in low-cost roll-to-roll manufacturing.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Changchun 130022, People’s Republic of China.
authors.forename: Shuyan
authors.initials: S
authors.lastname: Shao
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Jidong
authors.initials: J
authors.lastname: Zhang
authors.forename: Baohua
authors.initials: B
authors.lastname: Zhang
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Xie
authors.forename: Yanhou
authors.initials: Y
authors.lastname: Geng
authors.forename: Lixiang
authors.initials: L
authors.lastname: Wang
mesh_terms: D003300:Copper / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D012993:Solar Energy; D013499:Surface Properties; D013876:Thiophenes / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry
chemical_list: C539575:(6,6)-phenyl C61-butyric acid methyl ester; D037741:Fullerenes; D011137:Polystyrenes; D013876:Thiophenes; D017971:Tin Compounds; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); C507295:poly(3-hexylthiophene); C109984:indium tin oxide; D003300:Copper