April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
EL04.13.02

Static and time-dependent optical properties of CuI

When and Where

Apr 26, 2024
10:45am - 11:00am
Room 345, Level 3, Summit

Presenter(s)

Co-Author(s)

Andre Schleife1,Brian Robinson1

University of Illinois at Urbana-Champaign1

Abstract

Andre Schleife1,Brian Robinson1

University of Illinois at Urbana-Champaign1
We aim to use first-principles electronic-structure theory to explain the static and time-dependent optical properties of the wide-band gap semiconductor CuI, which is a promising candidate for a transparent conducting material. In particular, we aim to clarify the importance of the spin-orbit interaction for the appearance of an above-gap spectral feature that is reported in multiple experiments. Measurements of the linear optical properties that have been reported in the literature agree in attributing that peak in the spectrum to a spin-orbit split-off valence-band state. However, the significant oscillator strength of the peak might raise doubts about its origin due to the spin-orbit interaction. We use a combination of density-functional and many-body perturbation theory to simulate the electronic structure and optical properties including excitonic effects. Our simulations do not reproduce the experimentally reported peak structure and we show that the optical dipole transitions from the corresponding spin-orbit split-off electronic state do not show a polarization dependence. We interpret this as an indication that more direct experimental evidence is needed to support the spin-orbit origin of any feature in this spectral range. We also solve the Boltzmann transport equation to account for electron-phonon scattering as a relaxation mechanism in pump-probe experiments and implement the resulting time-dependent occupation numbers as constraint in simulations of the spectrum. Our predicted pump-probe spectra for this material show that increasing the intensity of the excitation only significantly changes the magnitude of the spectrum values, while increasing the excitation energy leads to changes in the presence of peaks, peak location, and peak width.

Symposium Organizers

Hideki Hirayama, RIKEN
Robert Kaplar, Sandia National Laboratories
Sriram Krishnamoorthy, University of California, Santa Barbara
Matteo Meneghini, University of Padova

Symposium Support

Silver
Taiyo Nippon Sanso

Session Chairs

Robert Kaplar
Sriram Krishnamoorthy

In this Session