Very fast hot carrier diffusion in unconstrained MoS₂on a glass substrate: discovered by picosecond ET-Raman

Abstract

Very high nonmonotonic thickness-dependent hot carrier diffusivity of MoS2in a normal-κdielectric screening environment was discovered by ET-Raman technique.

Review on Techniques for Thermal Characterization of Graphene and Related 2D Materials

“…The specific process is described in detail in the reference [32]. The electron-hole diffusion has a negligible effect on the thermal conduction in suspended 2D materials [33]. However, the effect of the hot carrier diffusion should be carefully handled when determining the interface thermal energy transport between graphene and substrate.…”

“…In order to resolve the challenges mentioned above in the optothermal Raman technique, various Raman-based techniques, including frequency-domain energy transport state-resolved Raman (FET-Raman) [35,36] and energy transport state-resolved Raman (ET-Raman) [33], were developed. They can free the Raman thermometry from the laser absorption and the temperature coefficient calibration.…”

“…To consider the hot carrier diffusion effect in the thermal transport in 2D materials, Yuan et al, first developed the ET-Raman to determine the interface thermal resistance and hot carrier diffusion coefficient in MoS 2 supported by c-Si [27,33]. The ET-Raman includes two energy transport states: the zero thermal transport state and the steady-state thermal transport.…”

Thermal conductance between water and nm-thick WS2: extremely localized probing using nanosecond energy transport state-resolved Raman

“…41 They reported other works that successfully measured the ITR between thin layers of TMD materials and glass or Si substrate. [42][43][44] Raman spectroscopy based techniques have the advantage of being non-contact, non-invasive, and material-specific that leads to higher accuracy of measured parameters.…”

Energy and Charge Transport in 2D Atomic Layer Materials: Raman-Based Characterization

“…In this work, the constructed two energy transport states are in spatial domain. To be fully free from the large errors of laser absorption evaluation and temperature coefficient calibration, a further developed technique named energy transport state-resolved Raman (ET-Raman) is developed to determine R and D [ 30 , 31 ]. In this technique, three distinct energy transport states in both spatial and time domains are constructed to probe materials’ thermal response.…”