Molecular order of air-stable p-type organic thin-film transistors by tuning the extension of the pi-conjugated core: the cases of indolo[3,2-b]-carbazole and triindole semiconductors

Abstract

Charge transport in organic devices depends strongly on the molecular order and morphology of the organic semiconductor thin films. In the design of new organic semiconductors, the selection of the appropriate core plays a key role in the molecular packing and charge transport characteristics of the organic device. Four derivatives of carbazole that mainly differ in the extension of the pi-conjugated core, including indolo[3,2-b] carbazole and triindole derivatives, exhibited hole mobilities ranging from 10(-5) to 10(-2) cm(2) V-1 s(-1) as active layers in organic thin-film transistors (OTFTs). X-ray analyses of the single crystals and evaporated thin films gave insights into the molecular packing of the compounds that justified their OTFTs characteristics.