All-polymer field-effect transistors using a brush gate dielectric

Interfaces between a poly(3-hexylthiophene) [P3HT] and an end-grafted (brush) layer of poly(methyl methacrylate) [PMMA] are shown using neutron reflectometry to be dependent on heat treatment. Annealing the samples allows part of the brush layer to cross into the P3HT layer creating a very asymmetric interface. We suggest that the P3HT rearrangement occurs, creating space for movement of the brush into the film. This interpenetration was observed with two different molecular weight (17.5 and 28 kg mol−1) P3HT films. Output characteristics of devices made from P3HT layers on PMMA brushes show that different amounts of heat treatment do not significantly change the device performance. Saturated hole mobilities are dependent on heat treatment, with devices made from a smaller molecular weight P3HT (22 kg mol−1) demonstrating larger mobilities than devices created using 48 kg mol−1 P3HT, but only after heat treatment.

[1]  C. Singh,et al.  Correlation of charge transport with structural order in highly ordered melt-crystallized poly(3-hexylthiophene) thin films , 2013 .

[2]  Alberto Salleo,et al.  Moderate doping leads to high performance of semiconductor/insulator polymer blend transistors , 2013, Nature Communications.

[3]  Yong-Young Noh,et al.  Effects of gate dielectrics and their solvents on characteristics of solution-processed N-channel polymer field-effect transistors , 2012 .

[4]  R. J. Kline,et al.  Poly(3-hexylthiophene) and [6,6]-Phenyl-C61-butyric Acid Methyl Ester Mixing in Organic Solar Cells , 2012 .

[5]  U. Pietsch,et al.  Impact of Thermal Annealing on the Semicrystalline Nanomorphology of Spin-Coated Thin Films of Regioregular Poly(3-alkylthiophene)s as Observed by High-Resolution Transmission Electron Microscopy and Grazing Incidence X-ray Diffraction , 2012 .

[6]  Martin Brinkmann,et al.  Structure and morphology control in thin films of regioregular poly(3‐hexylthiophene) , 2011 .

[7]  W. Porzio,et al.  Depth-resolved molecular structure and orientation of polymer thin films by synchrotron X-ray diffraction , 2011 .

[8]  Zhenan Bao,et al.  Effects of Thermal Annealing Upon the Morphology of Polymer–Fullerene Blends , 2010 .

[9]  Hagen Klauk,et al.  Organic thin-film transistors. , 2010, Chemical Society reviews.

[10]  Henning Sirringhaus,et al.  Control of roughness at interfaces and the impact on charge mobility in all-polymer field-effect transistors , 2008 .

[11]  S. Yeates,et al.  Organic field effect transistors from ambient solution processed low molar mass semiconductor–insulator blends , 2008 .

[12]  Gregory L. Whiting,et al.  Organic Thin Film Transistors with Polymer Brush Gate Dielectrics Synthesized by Atom Transfer Radical Polymerization , 2008 .

[13]  Yong-Young Noh,et al.  Downscaling of self-aligned, all-printed polymer thin-film transistors. , 2007, Nature nanotechnology.

[14]  W. Huck,et al.  Polymer brushes via surface-initiated polymerizations. , 2004, Chemical Society reviews.

[15]  H. Sirringhaus,et al.  Observation of Field‐Effect Transistor Behavior at Self‐Organized Interfaces , 2004 .

[16]  Janos Veres,et al.  Gate Insulators in Organic Field-Effect Transistors , 2004 .

[17]  J. Pflaum,et al.  Effect of Molecular Weight and Annealing of Poly(3‐hexylthiophene)s on the Performance of Organic Field‐Effect Transistors , 2004 .

[18]  Zhenan Bao,et al.  Synthesis of polymer dielectric layers for organic thin film transistors via surface-initiated ring-opening metathesis polymerization. , 2004, Journal of the American Chemical Society.

[19]  Jean M. J. Fréchet,et al.  Controlling the Field‐Effect Mobility of Regioregular Polythiophene by Changing the Molecular Weight , 2003 .

[20]  W. Brittain,et al.  Polymer brushes: surface-immobilized macromolecules , 2000 .

[21]  Zhenan Bao,et al.  Materials and Fabrication Needs for Low-Cost Organic Transistor Circuits , 2000 .

[22]  E. W. Meijer,et al.  Two-dimensional charge transport in self-organized, high-mobility conjugated polymers , 1999, Nature.

[23]  J. Penfold,et al.  EVIDENCE FOR CAPILLARY WAVES AT IMMISCIBLE POLYMER/POLYMER INTERFACES , 1997 .

[24]  A. Karim,et al.  Interfacial segment density profiles of end-anchored polymers in a melt , 1992 .

[25]  Craig J. Hawker,et al.  Interdiffusion of PCBM and P3HT Reveals Miscibility in a Photovoltaically Active Blend , 2011 .

[26]  Mario Leclerc,et al.  A calorimetric study of the phase transitions in poly(3-hexylthiophene) , 1995 .

[27]  Joseph L. Keddie,et al.  Interface and surface effects on the glass-transition temperature in thin polymer films , 1994 .