Presentation Information

10:00 AM - 10:15 AM JST(1:00 AM - 1:15 AM UTC)

[25a-12F-5]Gigantic exciton shift current observed in MBE-grown CuI thin films

〇Masao Nakamura¹, Takahiro Yasunami², Yang-hao Chan^3,4, Yi-Shiuan Huang⁵, Guang-Yu Guo^4,5, Yajian Hu¹, Naoki Ogawa¹, Yiling Chiew¹, Xiuzhen Yu¹, Takahiro Morimoto², Naoto Nagaosa^1,2, Yoshinori Tokura^1,2,6, Masashi Kawasaki^1,2 (1.RIKEN CEMS, 2.Univ. of Tokyo, 3.Academia Sinica, 4.NCTS, 5.National Taiwan Univ., 6.Tokyo College)

Keywords:

exciton,photovoltaic effect,wide-gap semiconductor

Shift current is a topological photocurrent driven by a change in the Berry connection upon optical transition. Since shift current does not require photo-excited free carriers as in ordinary photocurrent, it can in principle be generated by the creation of excitons, which are charge-neutral quasiparticles. Copper iodide (CuI), which has non-centrosymmetric crystal structure and exhibits a strong exciton response, is an ideal compound for demonstrating this exciton shift current. In this study, we successfully observe the exciton shift current as a DC current in high-quality CuI thin films fabricated by MBE.

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