title: Enhanced performance and stability of polymer BHJ photovoltaic devices from dry transfer of PEDOT:PSS.
abstract: Polymer solar cells with enhanced initial cell performances and long-term stability were fabricated by performing a simple dry transfer of a hole extraction layer [poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)] onto an indium tin oxide (ITO) substrate. Due to the very flat surface of the polyurethane acrylate/polycarbonate (PUA/PC) film, which was used as a mold and resembled the surface of the original substrate (silicon wafer), the transferred layer had a very smooth surface morphology, resulting in enhancement of the interfacial characteristics. The work function of the PEDOT:PSS layer and the morphology of bulk hetero junction (BHJ) layer were tuned by controlling the position of PSS enrichment in the PEDOT:PSS layer using the dry transfer. The power conversion efficiency of PTB7:PC71 BM BHJ device prepared by the dry transfer was 8.06%, which was significantly higher than that of the spin-cast device (7.32%). By avoiding direct contact between the ITO substrate and the PEDOT:PSS solution in the dry transfer system, etching and diffusion of indium in the ITO substrate were greatly reduced, thereby improving the stability.
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT) and School of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746 (Republic of Korea).
authors.forename: Jung Kyu
authors.initials: JK
authors.lastname: Kim
authors.forename: Insun
authors.initials: I
authors.lastname: Park
authors.forename: Wanjung
authors.initials: W
authors.lastname: Kim
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Wang
authors.forename: Dae-Geun
authors.initials: DG
authors.lastname: Choi
authors.forename: Yeong Suk
authors.initials: YS
authors.lastname: Choi
authors.forename: Jong Hyeok
authors.initials: JH
authors.lastname: Park
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D011211:Electric Power Supplies; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012993:Solar Energy; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D011108:Polymers; D011137:Polystyrenes; D017971:Tin Compounds; C121383:poly(3,4-ethylene dioxythiophene); C003321:polystyrene sulfonic acid; C109984:indium tin oxide
keywords: electrochemistry; hole extraction layer; polymer solar cells; power conversion efficiency; stamping-transfer