| Time：1141210 (Wed.) 14:20~16:20 Speaker：Prof.連德軒/ Lien, Der-Hsien 國立陽明交通大學電機工程學系/Department of Electronics and Electrical Engineering, National Yang Ming Chiao Tung University Title：Physics and scaling effect in ultrathin semiconductors Abstract： Dimensional scaling fundamentally reshapes the physical properties of two-dimensional and ultrathin semiconductors, governing their optical and electrical properties. In layered materials such as TMDCs, reducing thickness enhances excitonic effects due to quantum confinement and reduced dielectric screening, leading to tunable bandgaps and high photoluminescence efficiency. These excitonic characteristics define the optoelectronic performance of atomically thin 2D crystals. In contrast, disordered semiconductors exhibit percolation-limited transport, where scaling in all spatial dimensions alters the percolation threshold through path-confinement. This geometric constraint modulates the availability of conductive pathways and directly impacts threshold voltage and switching behavior. Percolation effects occur at micrometer-scale dimensions, independent of electrostatic short-channel effects or quantum confinement. Experimental results from amorphous n-type and p-type transistors confirm a universal scaling behavior governed by their percolation behavior. Together, I show that dimensional scaling leads to distinct behaviors in ordered and disordered semiconductors, highlighting material topology as a critical factor for designing devices based on low-dimensional physics. Place：S101, Gongguan Campus, NTNU |
