title: Gated three-terminal device architecture to eliminate persistent photoconductivity in oxide semiconductor photosensor arrays.
abstract: The composition of amorphous oxide semiconductors, which are well known for their optical transparency, can be tailored to enhance their absorption and induce photoconductivity for irradiation with green, and shorter wavelength light. In principle, amorphous oxide semiconductor-based thin-film photoconductors could hence be applied as photosensors. However, their photoconductivity persists for hours after illumination has been removed, which severely degrades the response time and the frame rate of oxide-based sensor arrays. We have solved the problem of persistent photoconductivity (PPC) by developing a gated amorphous oxide semiconductor photo thin-film transistor (photo-TFT) that can provide direct control over the position of the Fermi level in the active layer. Applying a short-duration (10 ns) voltage pulse to these devices induces electron accumulation and accelerates their recombination with ionized oxygen vacancy sites, which are thought to cause PPC. We have integrated these photo-TFTs in a transparent active-matrix photosensor array that can be operated at high frame rates and that has potential applications in contact-free interactive displays.
authors.forename: Sanghun
authors.initials: S
authors.lastname: Jeon
authors.forename: Seung-Eon
authors.initials: SE
authors.lastname: Ahn
authors.forename: Ihun
authors.initials: I
authors.lastname: Song
authors.forename: Chang Jung
authors.initials: CJ
authors.lastname: Kim
authors.forename: U-In
authors.initials: UI
authors.lastname: Chung
authors.forename: Eunha
authors.initials: E
authors.lastname: Lee
authors.forename: Inkyung
authors.initials: I
authors.lastname: Yoo
authors.forename: Arokia
authors.initials: A
authors.lastname: Nathan
authors.forename: Sungsik
authors.initials: S
authors.lastname: Lee
authors.forename: John
authors.initials: J
authors.lastname: Robertson
authors.forename: Kinam
authors.initials: K
authors.lastname: Kim