  2D materials are considered a key element in the development of
next-generation electronics (nanoelectronics) due to their extreme thickness in
the nanometer range and unique physical properties. The ultrafast dynamics of
photoexcited carriers in such materials are strongly influenced by their
interfaces, since the thickness of 2D materials is much smaller than the
typical depth of light penetration into their bulk counterparts and the mean
free path of photoexcited carriers. The resulting collisions of photoexcited
carriers with interfacial potential barriers of 2D materials in the presence of
a strong laser field significantly alter the overall dynamics of
photoexcitation, allowing laser light to be directly absorbed by carriers in
the conduction/valence band through the inverse bremsstrahlung mechanism. The
corresponding ultrafast carrier dynamics can be monitored using
multiphoton-pumped UV-Vis transient absorption spectroscopy. In this review, we
discuss the basic concepts and recent applications of this spectroscopy for a
variety of 2D materials, including transition-metal dichalcogenide monolayers,
topological insulators, and other 2D semiconductor structures.
