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Optical properties of MoOCl2: Anisotropic plasma frequencies, effective masses, and interband excitations

Maryam Rezvani Amin, Marco Naumann, Falk Röder, Bernd Büchner, and Martin Knupfer

Xianjie Liu

Jinpeng Yang

Xu Gao

Bo Xu

  • Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden

  • College of Physical Science and Technology, Yangzhou University, Jiangsu 225009, People's Republic of China

  • Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu 215123, People's Republic of China

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Phys. Rev. B 114, 175120 – Published 15 September, 2026

DOI: https://doi.org/10.1103/6t8r-svlf

Abstract

MoOCl2 is a metallic, layered van der Waals material with a strong in-plane structural anisotropy. The reflectivity of a MoOCl2 single crystal has been determined in a wide spectral range from the infrared to the visible regime. This reflectivity is extremely anisotropic, reflecting the anisotropic crystal structure and electronic properties of MoOCl2. Using a Drude–Lorentz fit, we extracted the dielectric function quantitatively for the two in-plane directions of MoOCl2, and we determined the anisotropic optical effective mass of the conduction electrons. Our data additionally demonstrate the presence of interband excitations in the measured spectral range.

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Phys. Rev. B 114, 175120– Published 15 September, 2026
  • Received 27 April 2026
  • Revised 29 June 2026
  • Accepted 17 August 2026
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