title: A Study on Reducing Contact Resistance in Solution-Processed Organic Field-Effect Transistors.
abstract: We report on the reduction of contact resistance in solution-processed TIPS-pentacene (6,13-bis(triisopropylsilylethynyl)pentacene) and PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) top-gate bottom-contact organic field-effect transistors (OFETs) by using different contact-modification strategies. The study compares the contact resistance values in devices that comprise Au source/drain electrodes either treated with 2,3,4,5,6-pentafluorothiophenol (PFBT), or modified with an evaporated thin layer of the metal-organic molecular dopant molybdenum tris-[1,2-bis(trifluoromethyl)ethane-1,2-dithiolene] (Mo(tfd)3), or modified with a thin layer of the oxide MoO3. An improved performance is observed in devices modified with Mo(tfd)3 or MoO3 as compared to devices in which Au electrodes are modified with PFBT. We discuss the origin of the decrease in contact resistance in terms of increase of the work function of the modified Au electrodes, Fermi-level pinning effects, and decrease of bulk resistance by electrically doping the organic semiconductor films in the vicinity of the source/drain electrodes.
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Sangmoo
authors: S
authors: Choi
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Canek
authors: C
authors: Fuentes-Hernandez
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Cheng-Yin
authors: CY
authors: Wang
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Talha M
authors: TM
authors: Khan
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Felipe A
authors: FA
authors: Larrain
authors: Center for Organic Photonics and Electronics (COPE), School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors: Yadong
authors: Y
authors: Zhang
authors: Center for Organic Photonics and Electronics (COPE), School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors: Stephen
authors: S
authors: Barlow
authors: Center for Organic Photonics and Electronics (COPE), School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors: Seth R
authors: SR
authors: Marder
authors: Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250, United States.
authors: Bernard
authors: B
authors: Kippelen
keywords: Fermi-level pinning; TIPS-pentacene/PTAA; contact doping; contact resistance; molybdenum trioxide; molybdenum tris-[1,2-bis(trifluoromethyl)ethane-1,2-dithiolene]; organic field-effect transistors; top-gate geometry