Deciphering Charge Carrier Dynamics of 2H-MoTe₂ with Attosecond Transient Grating Spectroscopy

2H-MoTe₂ is a semiconducting material with complex carrier dynamics due to its rich polymorphism and diverse physical properties. With the novel attosecond transient grating spectroscopy (ATGS), carrier dynamics can be explored on an ultrafast timescale with background-free signals and element specificity. In ATGS, two crossed near infrared pumps create a carrier grating and a time-delayed extreme ultraviolet probe, generated via high harmonics generation, is diffracted by said grating. We aim to apply ATGS on 2H-MoTe₂ as a proof of the ATGS technique and to acquire new information on MoTe₂ carrier properties. ATGS signal revealed carrier properties such as an electron-hole recombination lifetime of 1.4 ps, a timescale characteristic of MoTe₂ (​​Attar et al, ACS Nano 2020 14 (11)). Furthermore, energetically distinct hole and electron signals were observed, highlighting ATGS’ ability to separately probe electron and hole distributions, providing the advantage of straightforward interpretation of carrier dynamics. In the future, we hope to increase the signal-to-noise ratio with improved masking from scattered light, and to investigate MoTe₂ carrier diffusion, a key process that is uniquely probed by ATGS.