| 학회 | 한국재료학회 |
| 학술대회 | 2017년 가을 (11/15 ~ 11/17, 경주 현대호텔) |
| 권호 | 23권 2호 |
| 발표분야 | 2. 2차원 반도체 합성 및 소자 응용(Synthesis and device applications of two-dimensional semiconductors) |
| 제목 | Flexible/Wearable Electronics with 2D Materials and Pulsed Laser Processing |
| 초록 | We cannot image that people can live without electrical devices, nowadays. Therefore, interaction and interconnection between human and device are becoming more and more important with the lapse of time. Flexible and wearable electronics are envisioned as a future platform of electronics integrated into a variety of emerging technologies from sensing and monitoring to human-inspired applications; it is easy-to-read, lightweight, portable, flexible, and unbreakable. However, typical soft materials that can be used for the substrates of flexible/wearable electronics have a low thermal budget. Therefore, conventional high temperature thermal processes cannot be applied as they affect the entire parts, including unwanted areas where the process should be excluded. It can make the limitations of process temperature and the challenges in terms of compatibility with the other components that need to be integrated onto them. Unlike conventional process, a pulsed laser with high energy density leads to the thermal effect in locally confined area (i.e. small heat-affected zone) where requires high temperature without extreme thermal damage. Moreover, laser processing has other irreplaceable advantages: spatially local selective, air-stable, and widely tunable by varying the duration, wavelength, and intensity. First, I demonstrate that mechanically flexible multilayered MoS2 thin-film transistors (TFTs) in which the source/drain electrodes are selectively annealed using picosecond laser achieve the enhancement of device performance without plastic deformation, such as boosted mobility, increased output resistance, and decreased subthreshold swing. Numerical thermal simulation for the temperature distribution, transmission electron microscopy (TEM) analysis, current-voltage measurements, and contact-free mobility extracted from the Y-function method (YFM) enable understanding of the compatibility and the effects of pulsed laser annealing process; the enhanced performance originated not only from a decrease in the Schottky barrier effect at the contact, but also an improvement of the channel interface. Furthermore, laser process is also applied to the welding for fabricating mechanically robust and electrically attractive 2D-like random networks. The laser welding is compatible with cost-effective solution process and good for the flexible applications. After the laser welding, the sheet resistance of 2D-like networks created by silver nanowires is significantly improved. Note that the best improvement is around 55 times without any degradation of the electrical performances during cycling bending test. These various outcomes indicate that the site selective pulsed laser process can open up next-generation technologies and leading the paradigm shift of the electronic applications. |
| 저자 | 권혁준 |
| 소속 | 대구경북과학기술원 (DGIST) |
| 키워드 | MoS2; Pulsed Laser Process; Transistors; Flexible Electronics |
