title: Physically responsive field-effect transistors with giant electromechanical coupling induced by nanocomposite gate dielectrics.
abstract: Physically responsive field-effect transistors (physi-FETs) that are sensitive to physical stimuli have been studied for decades. The important issue for separating the responses of sensing materials from interference by other subcomponents in a FET transducer under global physical stimuli has not been completely resolved. In addition, challenges remain with regard to the design and employment of smart materials for flexible physi-FETs with a large electro-physical coupling effect. In this article, we propose the direct integration of nanocomposite (NC) gate dielectrics of barium titanate (BT) nanoparticles (NPs) and highly crystalline poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) into flexible organic FETs to achieve a large electro-physical coupling effect. Additionally, a new alternating current biasing method is proposed for precise extraction and quantification of tiny variations in the remnant polarization of NCs caused by mechanical stimuli. An investigation of physi-FETs under static mechanical stimuli revealed the first ever reported giant, positive piezoelectric coefficients of d(33) up to 960 pC/N in the NCs. The large coefficients are presumably due to the significant contributions of the intrinsic positive piezoelectricity of the BT NPs and P(VDF-TrFE) crystallites.
authors.affiliation: School of Advanced Materials Science & Engineering, Sungkyunkwan University (SKKU), Suwon, Kyunggi-do 440-746, Korea.
authors.forename: Nguyen Thanh
authors.initials: NT
authors.lastname: Tien
authors.forename: Tran Quang
authors.initials: TQ
authors.lastname: Trung
authors.forename: Young Gug
authors.initials: YG
authors.lastname: Seoul
authors.forename: Do Il
authors.initials: DI
authors.lastname: Kim
authors.forename: Nae-Eung
authors.initials: NE
authors.lastname: Lee