Control of carrier density by self-assembled monolayers in organic field-effect transistors.
Organic thin-film transistors are attracting a great deal of attention due to the relatively high field-effect mobility in several organic materials. In these organic semiconductors, however, researchers have not established a reliable method of doping at a very low density level, although this has been crucial for the technological development of inorganic semiconductors. In the field-effect device structures, the conduction channel exists at the interface between organic thin films and SiO(2) gate insulators. Here, we discuss a new technique that enables us to control the charge density in the channel by using organosilane self-assembled monolayers (SAMs) on SiO(2) gate insulators. SAMs with fluorine and amino groups have been shown to accumulate holes and electrons, respectively, in the transistor channel: these properties are understood in terms of the effects of electric dipoles of the SAMs molecules, and weak charge transfer between organic films and SAMs.
Kobayashi
S
S
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
Nishikawa
T
T
Takenobu
T
T
Mori
S
S
Shimoda
T
T
Mitani
T
T
Shimotani
H
H
Yoshimoto
N
N
Ogawa
S
S
Iwasa
Y
Y
D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008958:Models, Molecular; D008968:Molecular Conformation; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014173:Transistors, Electronic
D009930:Organic Chemicals; D012821:Silanes; D012822:Silicon Dioxide