Effect of post-deposition annealing temperature on the charge carrier mobility and morphology of DPPDTT based organic field effect transistors

[Display omitted] •The effect of post-deposition annealing on the charge carrier mobility of the DPPDTT based OFET was investigated.•The mobility was maximum for 100 °C annealed OFET that showed maximum grain size.•The films morphology and mobility of the annealed OFETs showed a strong correlation.•The results could provide insight on improving the charge carrier mobility for ambient operated OFETs. There is a considerable research interest in enhancing the charge carrier mobility of polymer-based organic field effect transistors (OFETs) through processing techniques. Herein, we investigate the effect of post-deposition annealing temperature on morphology and mobility of solution processible polymer Poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)], (DPPDTT) based OFETs. The resulting change in the grain size is proportional to the mobility data. At temperatures higher than 100 °C, grain size decreased with obvious desorption due to low Van der Waals forces in the polymer. Our results will hence contribute towards understanding the annealing mechanism in polymers to optimize the performance of DPPDTT based devices.