Enhancement of field-effect mobility due to structural ordering in poly(3-hexylthiophene) films by the dip-coating technique

Abstract

Organic field-effect transistors (OFETs) were fabricated by depositing a regioregular poly(3-hexylthiophene) (P3HT) active layer using a dip-coating method. The field-effect mobility in OFETs depends on chain orientation and crystallinity and is related to direction and withdrawal speed with respect to the source/drain orientation. In this paper, how to control the structural and transport properties of P3HT films by coating parallel and perpendicular to the dipping direction is demonstrated. X-ray diffraction curves taken in the perpendicular direction exhibit a higher degree of crystalline ordering and edgeon conformation compared with those in the parallel direction; this finding correlates with the directional anisotropy of the OFET mobility. Both structural anisotropy and transport properties are enhanced upon thermal treatment.

Fabrication of poly(3-hexylthiophene) nanowires for high-mobility transistors

“…However, typical values for non-SAM-treated devices are closer to 10 À3 cm 2 / Vs, which is in line with our non-solvated OFETs [47]. The average field effect mobility in our solvated OFETs, calculated in the saturated region, is 1.82 Â 10 À2 cm 2 /Vs, with champion devices showing mobility of up to 3.35 Â 10 À2 cm 2 /Vs.…”

Local scale structural changes of working OFET devices

“…Among the various conjugated polymers, poly(3-hexylthiophene) (P3HT) is widely used acting as workhorse for organic electronic applications. 3,4 Numerous studies have been performed towards enhancement of the P3HT microstructure, for example by annealing, flow coating, 5 dip-coating, 6 rubbing 7 or self-seeding techniques. 8 In recent years a strong effort has been placed towards in situ characterizations of P3HT active layers for OFETs 9,10 or P3HT/fullerene blends 11,12 for organic solar cells.…”

Versatile Organic Transistors by Solution Processing

“…Al arge number of creative, cost-effective techniques based on rapid, simple manufacturing schemes were designed and implemented for the fabrication of organic devices. Techniques such as inkjet printing, [21,126] spray deposition, [125] solution shearing, [42] andd ip coating, [151] among others, takeadvantage of the solution processability and allow film deposition at al ow cost per unit volume. Separately or together,t hese techniques offer considerable advantage over the energy-intensive practices such as RF sputtering, thermalo re lectron beam evaporation, chemical vapor deposition, and atomic layer deposition, which require high temperature, high vacuum, or both.…”