Understanding the interactions and emerging new properties in two-dimensional heterostructures

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K04995
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nanomaterials chemistry
• Research Institution: Okinawa Institute of Science and Technology Graduate University
• Principal Investigator: Man Michael 沖縄科学技術大学院大学, フェムト秒分光法ユニット, 研究員 (50793022)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: time resolved ARPES / ARPES / ultrafast / exciton dynamics / 2D materials

Outline of Final Research Achievements

This research uses time-resolved and angle resolved photoemission spectroscopy (tr-ARPES) to study electron dynamics in monolayer two-dimensional (2D) semiconductors materials. In this research, we observed exciton formations in exfoliated monolayer WSe2 in our laboratory based spatially resolved ARPES setup. Different scattering dynamics between direct and indirect excitons has been observed during resonant and off-resonant excitation. In additional, we directly measured the wavefunction of different excitonic species in real and momentum space. Part of this research has been reported in the LEEM/PEEM 11 Workshop and currently we have a manuscript under review.

Free Research Field

photoemission spectroscopy

Academic Significance and Societal Importance of the Research Achievements

In semiconductor systems, the absorption of light results in the formation of excitons, an electron and hole pairs. These excitons govern how materials react to light. In this research, we succeeded in visualizing excitons experimentally, and we advanced our understanding of exciton physics.