Investigating the photo-excited electronic state of a spin-valley coupled semiconductor

2016 Fiscal Year Final Research Report

• Project/Area Number: 16K13815
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: Ishizaka Kyoko 東京大学, 大学院工学系研究科(工学部), 准教授 (20376651)
• Project Period (FY): 2016-04-01 – 2017-03-31
• Keywords: 光電子分光 / 超高速現象 / 半導体

Outline of Final Research Achievements

We investigated the ultrafast dynamics of the electronic structure in a non-centrosymmetric spin-valley coupled semiconductor 3R-MoS2, by utilizing the femto-second time-resolved photoemission spectroscopy. In the time region of several picoseconds after the photoexcitation, we found the electron transferring from the valence band to the conduction band, with the simultaneous decrease of the band gap. The systematic time delay dependence indicates that the suppression of the band gap is closely related to the electron-hole excited state.

Free Research Field

物性物理実験