Quantifying Resistances across Nanoscale Low- and High-Angle Interspherulite Boundaries in Solution-Processed Organic Semiconductor Thin Films
- 30 September 2012
- journal article
- Published by American Chemical Society (ACS) in ACS Nano
- Vol. 6 (11), 9879-9886
- https://doi.org/10.1021/nn303446h
Abstract
The nanoscale boundaries formed when neighboring spherulites impinge in polycrystalline, solution-processed organic semiconductor thin films act as bottlenecks to charge transport, significantly reducing organic thin-film transistor mobility in devices comprising spherulitic thin films as the active layers. These interspherulite boundaries (ISBs) are structurally complex, with varying angles of molecular orientation mismatch along their lengths. We have successfully engineered exclusively low- and exclusively high-angle ISBs to elucidate how the angle of molecular orientation mismatch at ISBs affects their resistivities in triethylsilylethynyl anthradithiophene thin films. Conductive AFM and four-probe measurements reveal that current flow is unaffected by the presence of low-angle ISBs, whereas current flow is significantly disrupted across high-angle ISBs. In the latter case, we estimate the resistivity to be 22 MΩμm2/width of the ISB, only less than a quarter of the resistivity measured across low-angle grain boundaries in thermally evaporated sexithiophene thin films. This discrepancy in resistivities across ISBs in solution-processed organic semiconductor thin films and grain boundaries in thermally evaporated organic semiconductor thin films likely arises from inherent differences in the nature of film formation in the respective systems.Keywords
This publication has 28 references indexed in Scilit:
- Tuning charge transport in solution-sheared organic semiconductors using lattice strainNature, 2011
- Structural Complexities in the Active Layers of Organic ElectronicsAnnual Review of Chemical and Biomolecular Engineering, 2010
- Controlling Nucleation and Crystallization in Solution‐Processed Organic Semiconductors for Thin‐Film TransistorsAdvanced Materials, 2009
- Control of the Morphology and Structural Development of Solution‐Processed Functionalized Acenes for High‐Performance Organic TransistorsAdvanced Functional Materials, 2009
- Charge‐Transport Anisotropy Due to Grain Boundaries in Directionally Crystallized Thin Films of Regioregular Poly(3‐hexylthiophene)Advanced Materials, 2009
- Stable Solution-Processed High-Mobility Substituted Pentacene SemiconductorsChemistry of Materials, 2006
- Improving Organic Thin‐Film Transistor Performance through Solvent‐Vapor Annealing of Solution‐Processable Triethylsilylethynyl AnthradithiopheneAdvanced Materials, 2006
- Dependence of Regioregular Poly(3-hexylthiophene) Film Morphology and Field-Effect Mobility on Molecular WeightMacromolecules, 2005
- Organic Thin Film Transistors for Large Area ElectronicsAdvanced Materials, 2002
- High-Resolution Inkjet Printing of All-Polymer Transistor CircuitsScience, 2000