Probing Carrier Dynamics in Large-Scale MBE-Grown PtSe2 Films by Terahertz Spectroscopy

Jie Ji; Yingqiu Zhou; Binbin Zhou; Eva Desgué; Pierre Legagneux; Peter Uhd Jepsen; Peter Bøggild

doi:10.1021/acsami.3c09792

Probing Carrier Dynamics in Large-Scale MBE-Grown PtSe₂ Films by Terahertz Spectroscopy

ACS Appl Mater Interfaces. 2023 Oct 26. doi: 10.1021/acsami.3c09792. Online ahead of print.

Authors

Jie Ji¹, Yingqiu Zhou¹, Binbin Zhou², Eva Desgué³, Pierre Legagneux³, Peter Uhd Jepsen², Peter Bøggild¹

Affiliations

¹ Department of Physics, Technical University of Denmark, Kgs. Lyngby 2800, Denmark.
² Department of Electrical and Photonics Engineering, Technical University of Denmark, Kgs. Lyngby 2800, Denmark.
³ Thales Research and Technology, Palaiseau 91767, France.

PMID: 37883033
DOI: 10.1021/acsami.3c09792

Abstract

Atomically thin platinum diselenide (PtSe₂) films are promising for applications in the fields of electronics, spintronics, and photodetectors owing to their tunable electronic structure and high carrier mobility. Using terahertz (THz) spectroscopy techniques, we investigated the layer-dependent semiconducting-to-metallic phase transition and associated intrinsic carrier dynamics in large-scale PtSe₂ films grown by molecular beam epitaxy. The uniformity of large-scale PtSe₂ films was characterized by spatially and frequency-resolved THz-based sheet conductivity mapping. Furthermore, we use an optical-pump-THz-probe technique to study the transport dynamics of photoexcited carriers and explore light-induced intergrain carrier transport in PtSe₂ films. We demonstrate large-scale THz-based mapping of the electrical properties of transition metal dichalcogenide films and show that the two noncontact THz-based approaches provide insight in the spatial and temporal properties of PtSe₂ films.

Keywords: THz-TDS spectroscopy; carrier dynamics; large-scale TMD films; molecular beam epitaxy; phase transitions; ultrafast light-matter interactions.