title: Defects and Charge-Trapping Mechanisms of Double-Active-Layer In-Zn-O and Al-Sn-Zn-In-O Thin-Film Transistors.
abstract: Active matrix organic light-emitting diodes (AMOLEDs) are considered to be a core component of next-generation display technology, which can be used for wearable and flexible devices. Reliable thin-film transistors (TFTs) with high mobility are required to drive AMOLEDs. Recently, amorphous oxide TFTs, due to their high mobility, have been considered as excellent substitutes for driving AMOLEDs. However, the device instabilities of high-mobility oxide TFTs have remained a key issue to be used in production. In this paper, we present the charge-trapping and device instability mechanisms of high-mobility oxide TFTs with double active layers, using In-Zn-O (IZO) and Al-doped Sn-Zn-In-O (ATZIO) with various interfacial IZO thicknesses (0-6 nm). To this end, we employed microsecond fast current-voltage (I-V), single-pulsed I-V, transient current, and discharge current analysis. These alternating-current device characterization methodologies enable the extraction of various trap parameters and defect densities as well as the understanding of dynamic charge transport in double-active-layer TFTs. The results show that the number of defect sites decreases with an increase in the interfacial IZO thickness. From these results, we conclude that the interfacial IZO layer plays a crucial role in minimizing charge trapping in ATZIO TFTs.
authors.affiliation: Department of Applied Physics, Korea University , 2511 Sejongro, Sejong 339-700, Republic of Korea.
authors.forename: Youngin
authors.initials: Y
authors.lastname: Goh
authors.affiliation: Department of Applied Physics, Korea University , 2511 Sejongro, Sejong 339-700, Republic of Korea.
authors.forename: Taeho
authors.initials: T
authors.lastname: Kim
authors.affiliation: Electronics and Telecommunications Research Institute , 218 Gajeong-dong, Yuseong-gu, Daejeon 305-700, Republic of Korea.
authors.forename: Jong-Heon
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Electronics and Telecommunications Research Institute , 218 Gajeong-dong, Yuseong-gu, Daejeon 305-700, Republic of Korea.
authors.forename: Ji Hun
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Electronics and Telecommunications Research Institute , 218 Gajeong-dong, Yuseong-gu, Daejeon 305-700, Republic of Korea.
authors.forename: Chi-Sun
authors.initials: CS
authors.lastname: Hwang
authors.affiliation: Electronics and Telecommunications Research Institute , 218 Gajeong-dong, Yuseong-gu, Daejeon 305-700, Republic of Korea.
authors.forename: Sung Haeng
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Department of Applied Physics, Korea University , 2511 Sejongro, Sejong 339-700, Republic of Korea.
authors.forename: Sanghun
authors.initials: S
authors.lastname: Jeon
keywords: Al−Sn−Zn−In−O; charge trapping; defect density; double active layer; negative oxygen ion effect; oxide semiconductor; thin-film transistor