title: Origin of bias-stress induced instability in organic thin-film transistors with semiconducting small-molecule/insulating polymer blend channel.
abstract: The stabilities of a blending type organic thin-film transistor with phase-separated TIPS-pentacene channel layer were characterized under the conditions of negative-bias-stress (NBS) and positive-bias-stress (PBS). During NBS, threshold voltage (Vth) shifts noticeably. NBS-imposed devices revealed interfacial trap density-of-states (DOS) at 1.56 and 1.66 eV, whereas initial device showed the DOS at only 1.56 eV, as measured by photoexcited charge-collection spectroscopy (PECCS) method. Possible origin of this newly created defect is related to ester group in PMMA, which induces some hole traps at the TIPS-pentacene/i-PMMA interface. PBS-imposed device showed little Vth shift but visible off-current increase as "back-channel" effect, which is attributed to the water molecules trapped on the TFT surface.
authors: Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
authors: Ji Hoon
authors: JH
authors: Park
authors: Young Tack
authors: YT
authors: Lee
authors: Hee Sung
authors: HS
authors: Lee
authors: Jun Young
authors: JY
authors: Lee
authors: Kimoon
authors: K
authors: Lee
authors: Gyu Baek
authors: GB
authors: Lee
authors: Jiwon
authors: J
authors: Han
authors: Tae Woong
authors: TW
authors: Kim
authors: Seongil
authors: S
authors: Im