Monitoring substrate-induced electron–phonon coupling at interfaces of 2D organic/inorganic van der Waals heterostructures with in situ Raman spectroscopy

Multifunctional devices based on 2D organic/inorganic van der Waals heterostructures (2D OIHs) exhibit excellent properties due to extensive and flexible structural tunability. However, how to precisely regulate devices via in situ monitoring technique remains a great challenge, and corresponding development is still in its infancy. In this Letter, we show that Raman spectroscopy can serve as an effective in situ detection strategy to systematically observe the interfacial electron–phonon coupling (IEPC) between substrate and 2D OIHs. Combining non-adiabatic molecular dynamics simulations with ultrafast spectroscopy, we reveal that the different strengths of IEPC between substrates and 2D OIHs can directly modulate the photocarrier lifetimes of inorganic 2D materials, and therefore, indirectly modify the Raman-sensitive photo-induced charge transfer processes at the interface of 2D OIHs. Further in situ Raman evidence demonstrates the unique advantage of Raman spectroscopy with high sensitivity to monitor different substrate-induced IEPC under variable temperature.