| Time：1141029 (Wed.) 14:20~16:20 Speaker：Prof.林偉翔/ Lin, Wei-Hsiang 國立中興大學物理學系/Department of physics, National Chung Hsing University Title：Tailoring the Valley-Polarized Emission of Monolayer TMDs at Room Temperature for Future Quantum Information Technology Abstract： Monolayer transition metal dichalcogenides (TMDs) have intrinsic valley degrees of freedom, making them appealing for exploiting valleytronic applications in information storage and processing. WS2 monolayer possesses two inequivalent valleys in the Brillouin zone, each valley coupling selectively with a circular polarization of light. The degree of valley polarization (DVP) under the excitation of circularly polarized light (CPL) is a parameter that determines the purity of valley polarized photoluminescence (PL) of monolayer WS2. In this talk, I will introduce two strategies for tailoring valley polarization at room temperature (RT), aiming to enable more practical and application-oriented valleytronic devices. First, I will demonstrate how ultra-compact plasmonic Archimedes spiral (PAS) nanostructures enhance light–matter interactions via surface plasmons, thereby efficiently modulating the valley-polarized photoluminescence (PL) of monolayer WS₂ at RT. Finally, I will present my recent progress on ferroelectric Bi₂O₂Se nanosheets, and discuss my ongoing efforts to integrate Bi₂O₂Se nanosheets into valleytronic device architectures, paving the way for electrically tunable, energy-efficient valley-based technologies. These methodologies describe in this talk provide a promising platform to manipulate the valley degrees of freedom in TMDs efficiently at RT, paving ways for future applications of opto-valleytronic/spintronic devices based on these 2D materials. References: 1. Lin, W.H.*; Li, C.-S.; Wu C.-I; Rossman, G. R.; Atwater, H. A* and Yeh, N.-C.*, Dramatically Enhanced Valley-Polarized Emission by Alloying and Electrical Tuning of Monolayer WTe2xS2(1-x) Alloys at Room Temperature with 1T′-WTe2-Contact. Advanced Science 2023, 11(2), 2304890. 2. Lin, W.-H.*; Wu, P. C.; Akbari, H.; Rossman, G. R.; Yeh, N.-C.*; Atwater, H. A*. Electrically Tunable and Dramatically Enhanced Valley-Polarized Emission of Monolayer WS2 at Room Temperature with Plasmonic Archimedes Spiral Nanostructures. Advanced Materials 2022, 34 (3), 2104863. Place：S101, Gongguan Campus, NTNU |
