We investigated the hysteresis phenomenon in In-Ga-Zn-O thin-film transistors under light illumination. Hysteresis was observed under the 450-nm illumination and was increased with temperature. Light-induced hysteresis occurs due to increased subband-gap states at the interface between the gate-insulator layer and the active layer. Increased subband-gap states increase the subthreshold slope (SS) during the forward sweep. As temperature increases, the transition rate from neutral oxygen vacancy V O to doubly ionized oxygen vacancy V O 2+ increases under the same illumination conditions. The SS of the forward sweep increases with temperature due to the increase in V O 2+ states.
Bibliographical noteFunding Information:
Manuscript received May 10, 2012; accepted June 18, 2012. Date of publication August 6, 2012; date of current version August 21, 2012. This work was supported by the National Research Foundation of Korea funded by the Korean government (MEST) under Grant R0A-2007-000-20117-0. The review of this letter was arranged by Editor S. J. Koester. S.-H. Kuk, S.-Y. Lee, S.-J. Kim, and M.-K. Han are with the School of Electrical Engineering, Seoul National University, Seoul 151-742, Korea. B. Kim is with the School of Electrical Engineering, Seoul National University, Seoul 151-742, Korea, and also with the Research and Development Center, LG Display, Paju 413-811, Korea. S.-J. Park are with the Research and Development Center, LG Display, Paju 413-811, Korea. J.-Y. Kwon is with School of Integrated Technology, Yonsei University, Inchoen 406-840, Korea (e-mail: firstname.lastname@example.org). Color versions of one or more of the figures in this letter are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LED.2012.2205891
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering