Photo-controlled molecular growth and electrical performances of a pentacene-based organic transistor with a photo-reactive insulator

We investigate the initial molecular growth of the pentacene and the corresponding transistor performance by varying the exposure angle of linearly polarized ultraviolet (LPUV) light on a poly(methylmethacrylate) (PMMA)-based photo-reactive insulator. Based on the optically verified alignment features of pentacene molecules on the LPUV illuminated PMMA-based insulator, it is found that the initial size and the anisotropy of pentacene grains are gradually increased and finally saturated with increasing the exposure angle of the LPUV light. In such situation, the resultant electrical performance of the pentacene-based organic transistor are found to be monotonically enhanced up to a certain maximum at an optimal exposure angle of 30° and finally saturated.

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► Photo-controlled molecular growth at the initial stage was examined.
► The crystallographic orientation was studied as a function of LPUV exposure angle.
► The effect of the LPUV exposure angle onto the photo-sensitive layer was investigated.
► The resultant electrical properties and the physical origin were described.