Improving device performance of p-type organic field-effect transistor using butterfly like triarylamines

摘要

Facile and economic strategy to create a controlled self-structured architecture of semiconducting molecules is very crucial in the accomplishment of carbon electronic devices. A series of new unsymmetrically functionalized butterfly type triarylamines with electron donating/withdrawing substituents were synthesized. Simple and efficient solution based method was used as a successful strategy for OFET with improved characteristics. Binary solvent system with chloroform and toluene (7:3) has improved inter/intra molecular communication in the active layer. The morphology of the films was analyzed by SEM reveals the uniform packing. In addition post thermal annealing has enhanced the crystallinity with minimal grain boundaries. HOMO values -5.1 to -5.4 eV obtained from cyclic voltammetry ensure that these molecules can efficiently transport holes. OFET devices were fabricated in bottom gate top contact (BGTC) architecture by spin coating. Molecules exhibited typical p-channel transistor behavior with mobility up to 1 cm~2 V~(-1)s~(-1) with 10~6 I_(on/off) current ratio. Density functional theory (DFT) visualized the packing and interaction of molecules and supported the efficient mobility. Our investigation gives insight into the role of solvents to control the film architecture in solution processing OFET device construction.