Solution-processed organic field-effect transistors and unipolar inverters using self-assembled interface dipoles on gate dielectrics.
Self-assembled monolayers (SAMs) of polarized and nonpolarized organosilane molecules on gate insulators induced tunable threshold voltage shifting and current modulation in organic field-effect transistors (OFETs) made from solution-deposited 5,5'-bis(4-hexylphenyl)-2,2'-bithiophene (6PTTP6), defining depletion-mode and enhancement-mode operation. p-Channel inverters were made from pairs of OFETs with an enhancement-mode driver and a depletion-mode load to implement full-swing and high-gain organic logic circuits. The experimental results indicate that the shift of the transfer characteristics is governed by the built-in electric field of the SAM. The effect of surface functional groups affixed to the dielectric substrate on the grain appearance and film mobility is also determined.
Huang
Cheng
C
Department of Materials Science and Engineering and Department of Electrical and Computer Engineering, G. W. C. Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Katz
Howard E
HE
West
James E
JE