(Invited) Ultrafast Charge Transfer Dynamics in WS2–Au Nanohybrid System Fabricated by Pulsed Laser Ablation in Liquid

Abstract

Nanosheet semiconductor materials have attracted much attention in recent years due to their unique optical, electronic, and chemical properties for various applications such as photodetectors, light emitters, photocatalysts, and biosensors. We have fabricated tungsten disulfide (WS2) nanostructures by pulsed laser ablation in liquid. We applied nanosecond and femtosecond lasers and found the latter to be suitable for nanosheet fabrication [1]. Visible light response was enhanced by attaching gold nanoparticles (AuNPs) onto WS2 nanosheets [2]. The charge transfer dynamics in the WS2-Au nanohybrid system was characterized using femtosecond diffuse reflectance spectroscopy. The nanosheet structure was found to reduce the bulk carrier property. Furthermore, modification with AuNPs was found to enhance the formation of carriers trapped deeply in the WS2 nanosheets. These findings will be useful for the design of future metal-nanosheet semiconductor hybrid systems.Reference Pankaj Koinkar, Kohei Sasaki, Tetsuro Katayama and Akihiro Furube, International Journal of Modern Physics B, 35, 2140007 (2021)Tatsuki Kokufu, Daichi Nakayama, Tetsuro Katayama, Koinkar Pankaj, and Akihiro Furube, The 13th Asia-Pacific Conference on Near-Field Optics, OL30-A13 (2022)