Second Harmonic Generation and Exciton Binding Energies in ultrathin Copper Iodide
ORAL
Abstract
One of the central topics of condensed matter research is the behavior of excitons at a two-
dimensional (2D) limit. Copper Iodide (CuI) is a material that supports excitons with large
binding energies in bulk (≈60 meV) and likely also at atomic thicknesses. In this work, we grew
ultrathin layers of γ-phase CuI with heights ranging from 1-20 nm and then studied the second-
harmonic generation (SHG) and two-photon photoluminescence signals by using a femtosecond
laser with wavelengths ranging from 770-850 nm. We saw a consistent two-photon excitonic
emission peak of 406nm (3.05 eV) and an increasing SHG efficiency as the laser wavelength
approached the excitonic resonance.
dimensional (2D) limit. Copper Iodide (CuI) is a material that supports excitons with large
binding energies in bulk (≈60 meV) and likely also at atomic thicknesses. In this work, we grew
ultrathin layers of γ-phase CuI with heights ranging from 1-20 nm and then studied the second-
harmonic generation (SHG) and two-photon photoluminescence signals by using a femtosecond
laser with wavelengths ranging from 770-850 nm. We saw a consistent two-photon excitonic
emission peak of 406nm (3.05 eV) and an increasing SHG efficiency as the laser wavelength
approached the excitonic resonance.
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Presenters
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Chris Klenke
University of Arkansas
Authors
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Chris Klenke
University of Arkansas
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Sudeep Puri
University of Arkansas, Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
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Hiroyuki Nakamura
University of Arkansas, Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA