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

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 x 10(-3) cm(2)/V s and 7.5 x 10(-3) cm(2)/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. (C) 2015 Elsevier B.V. All rights reserved.