Crystalline TQPP as p-type semiconductor: X-ray crystallographic investigation, OTFT device, and computational analysis of transport properties

Abstract

Two p-type semiconducting azapyrenoacene materials, quinoxalino[2′,3′:9,10]phenanthro[4,5-abc]phenazine (TQPP) and 6,7,15,16-tetramethylquinoxalino[2′,3′:9,10]phenanthro[4,5-abc]phenazine (TQPP-[CH3]4), were characterized and were found to display high thermal stability and planar molecular geometry as revealed by single-crystal X-ray analysis. In bottom-gate p-channel organic thin-film transistors, field-effect mobilities of 2.5 × 10-3 cm2/V s and 7.5 × 10-5 cm2/V s were measured in ambient air for TQPP and TQPP-[CH3]4, respectively. Computational results of reorganization energies and electronic couplings indicate larger inter and intra-columnar couplings for TQPP-[CH3]4 in comparison to TQPP and predict the suitability of both semiconductors for hole as well as electron transporters. © 2015 Published by Elsevier B.V.