Pulsed laser annealing for advanced performance of mechanically flexible and optically transparent multilayer MoS2 transistors (Presentation Recording)

Laser enables the achievement of superb interfacial characteristics between electrode and semiconducting material contact surface and is also useful for a reduction in contact resistance. The irradiation of a pulsed laser with high energy density and short wavelength onto the electrodes leads to thermal annealing at the locally confined small area that needs high temperature without inflicting thermal damage. This contrasts conventional thermal annealing that affects the entire panel, including unwanted areas in which the annealing process should be excluded. We demonstrate that mechanically flexible and optically transparent (more than 81% transmittance in visible wavelength) multilayered molybdenum disulfide (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 higher 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, these results show that the laser annealing can be a promising technology to build up a high performance transparent and flexible electronics.