title: Probing Ternary Solvent Effect in High V(oc) Polymer Solar Cells Using Advanced AFM Techniques.
abstract: This work describes a simple method to develop a high V(oc) low band gap PSCs. In addition, two new atomic force microscopy (AFM)-based nanoscale characterization techniques to study the surface morphology and physical properties of the structured active layer are introduced. With the help of ternary solvent processing of the active layer and C60 buffer layer, a bulk heterojunction PSC with V(oc) more than 0.9 V and conversion efficiency 7.5% is developed. In order to understand the fundamental properties of the materials ruling the performance of the PSCs tested, AFM-based nanoscale characterization techniques including Pulsed-Force-Mode AFM (PFM-AFM) and Mode-Synthesizing AFM (MSAFM) are introduced. Interestingly, MSAFM exhibits high sensitivity for direct visualization of the donor-acceptor phases in the active layer of the PSCs. Finally, conductive-AFM (cAFM) studies reveal local variations in conductivity in the donor and acceptor phases as well as a significant increase in photocurrent in the PTB7:ICBA sample obtained with the ternary solvent processing.
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Mikhael
authors.initials: M
authors.lastname: Soliman
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|CREOL, College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Josie
authors.initials: J
authors.lastname: Lorenzo
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|CREOL, College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Nitesh
authors.initials: N
authors.lastname: Dhasmana
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|CREOL, College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Panit
authors.initials: P
authors.lastname: Chantharasupawong
authors.affiliation: The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.|Institute for Functional Imaging of Materials, Oak Ridge National Laboratory , 1 Bethel Valley Rd., Oak Ridge, Tennessee 37831, United States.
authors.forename: Anton V
authors.initials: AV
authors.lastname: Ievlev
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.|Department of Chemistry, University of Central Florida , Orlando, Florida 32816, United States.|CREOL, College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Andre J
authors.initials: AJ
authors.lastname: Gesquiere
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Laurene
authors.initials: L
authors.lastname: Tetard
authors.affiliation: NanoScience Technology Center, University of Central Florida , Orlando, Florida 32826, United States .|Department of Material Science and Engineering, University of Central Florida , Orlando, Florida 32816, United States.|CREOL, College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Jayan
authors.initials: J
authors.lastname: Thomas
keywords: cascade charge transfer; donor−acceptor phases; high Voc; polymer solar cell; ternary solvent