文摘
Proper functionalization of indolo[3,2-b]carbazole led to a new class of high-performance organicsemiconductors suitable for organic thin-film transistor (OTFT) applications. While 5,11-diaryl-substitutedindolo[3,2-b]carbazoles without long alkyl side chains provided amorphous thin films upon vacuumdeposition, those with sufficiently long alkyl side chains such as 5,11-bis(4-octylphenyl)indolo[3,2-b]carbazoleself-organized readily into highly crystalline layered structures under similar conditions. OTFTs using channelsemiconductors of this nature exhibited excellent field-effect properties, with mobility up to 0.12 cm2 V-1s-1 and current on/off ratio to 107. As this class of organic semiconductors has relatively low HOMO levelsand large band gaps, they also displayed good environmental stability even with prolonged exposure toamber light, an appealing characteristic for OTFT applications.