Direct measurement of photoinduced transient conducting state in multilayer 2H-MoTe2

Abstract

Ultrafast light-matter interaction has emerged as a powerful tool to control and probe the macroscopic properties of functional materials, especially two-dimensional transition metal dichalcogenides which can form different structural phases with distinct physical properties. However, it is often difficult to accurately determine the transient optical constants. In this work, we developed a near-infrared pump - terahertz to midinfrared (12-22 THz) probe system in transmission geometry to measure the transient optical conductivity in 2H-MoTe2 layered material. By performing separate measurements on bulk and thin-film samples, we are able to overcome issues related to nonuniform substrate thickness and penetration depth mismatch and to extract the transient optical constants reliably. Our results show that photoexcitation at 690 nm induces a transient insulator-metal transition, while photoexcitation at 2 um has a much smaller effect due to the photon energy being smaller than the band gap of the material. Combining this with a single-color pump-probe measurement, we show that the transient response evolves towards 1T' phase at higher flunece. Our work provides a comprehensive understanding of the photoinduced phase transition in the 2H-MoTe2 system.

arXiv comment9 pages, 11 figures

References in corpus (14)

• Observation of tightly bound trions in monolayer MoS2
• Superconductivity in Weyl Semimetal Candidate MoTe2
• Prediction of the Weyl semimetal in the orthorhombic MoTe2
• Structural Semiconductor-to-Semimetal Phase Transition in Two-Dimensional Materials Induced by Electrostatic Gating
• Trion induced negative photoconductivity in monolayer MoS2
• Arc-tunable Weyl Fermion metallic state in Mo${}_x$W${}_{1-x}$Te${}_2$
• Ultrafast and spatially resolved studies of charge carriers in atomically-thin molybdenum disulfide
• THz-pump -- THz-probe spectroscopy of semiconductors at high field strengths
• Light induced sub-picosecond topological phase transition in MoTe2
• Sub-picosecond photo-induced displacive phase transition in two-dimensional MoTe${}_2$
• Magnetic excitations of the field induced states in BaCo2(AsO4)2 probed by time-domain terahertz spectroscopy
• Field induced magnon excitation and in gap absorption of Kitaev candidate RuCl3
• Many-body recombination in insulating cuprates
• Tunable near- to mid-infrared pump terahertz probe spectroscopy in reflection geometry