Morphology control of TIPS-pentacene grains with inert gas injection and effects on the performance of OTFTs

We applied Ar gas injection while drying droplets of TIPS-pentacene in a quartz tube and controlled the growth direction of the grain boundary and the morphology. The organic thin film transistors (OTFTs) showed a high mobility of 0.53 ± 0.02 cm2/V s with a small deviation of 3.7% when the gas direction was parallel to the source–drain current, resulting in the direction of the grain boundary being parallel to the current. In contrast, OTFTs having grain boundaries perpendicular to the current flow displayed mobility of 0.06 ± 0.02 cm2/V s.

Figure optionsDownload as PowerPoint slideHighlights
► Ar gas was applied to the droplets of TIPS-pentacene during drying in quartz tube.
► The direction of grain boundary was controlled by Ar gas injection.
► An appropriate flow rate of Ar gas was required for uniform morphology of grains.
► The grain boundary parallel to current flow produced a mobility of 0.53 cm2/V·sec.
► The standard deviation of mobility averaged from 36 devices was very small; 3.7%.