A highly pi-stacked organic semiconductor for field-effect transistors based on linearly condensed pentathienoacene.
We present the synthesis and characterization of a fused-ring compound, dithieno[2,3-d:2',3'-d']thieno[3,2-b:4,5-b']dithiophene (pentathienoacene, PTA). In contrast to pentacene, PTA has a larger band gap than most semiconductors used in organic field-effect transistors (OFETs) and therefore is expected to be stable in air. The large pi-conjugated and planar molecular structure of PTA would also form higher molecular orders that are conductive for carrier transport. X-ray diffraction and atomic force microscopy experiments on its films show that the molecules stack in layers with their long axis upright from the surface. X-ray photoelectron spectroscopy suggests that there are no chemical bonds at the PTA/Au interface. OFETs based on the PTA have been constructed, and their performances as p-type semiconductors are also presented. A high mobility of 0.045 cm(2)/V s and an on/off ratio of 10(3) for a PTA OFET have been achieved, demonstrating the potential of PTA for application in future organic electronics.
Xiao
Kai
K
Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, P.R. China.
Liu
Yunqi
Y
Qi
Ting
T
Zhang
Wei
W
Wang
Fang
F
Gao
Jianhua
J
Qiu
Wenfeng
W
Ma
Yongqiang
Y
Cui
Guanglei
G
Chen
Shiyan
S
Zhan
Xiaowei
X
Yu
Gui
G
Qin
Jingui
J
Hu
Wenping
W
Zhu
Daoben
D
D004553:Electric Conductivity; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D012666:Semiconductors; D013696:Temperature; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry*; D014173:Transistors, Electronic
D013876:Thiophenes; C505705:dithieno(2,3-d-2',3'-d')thieno(3,2-b:4,5-b')dithiophene