Solution Shearing of a High‐Capacitance Polymer Dielectric for Low‐Voltage Organic Transistors.

With the prospect of realizing innovative technologies by large‐area fabrication at low cost and high throughput, printing and coating technologies are being intensively researched for the deposition of functional films. One promising coating technology is solution shearing, which has been studied as a deposition technique for organic semiconductors but not to a greater extent for dielectric layers. Therefore, the deposition by solution shearing of high‐quality poly(4‐vinylphenol) dielectrics is investigated, and the utility of these films as ultra‐smooth dielectric substrates for transistors is demonstrated. By comparing these films to those prepared by spin‐coating, it is possible to highlight the advantages of the technique. Specifically, thinner films with thicknesses as low as 11.4 nm but still low leakage and almost identical surface properties can be achieved. Thus, dielectric films with a very high capacitance of 280 nF cm‐2 are realized in a single coating step. Probing these films within organic transistors shows that they can facilitate operation at voltages as low as ‐1 V. Finally, it is shown how the use of a polymer‐small‐molecule–semiconductor blend can pave the way toward high‐performance, ultra‐low‐voltage devices from solution. [ABSTRACT FROM AUTHOR]