"Ultrafast Electronic and Structural Response of Monolayer MoS2 under Intense Photoexcitation Conditions"

Ehren M. Mannebach: Karel-Alexander N. Duerloo, Lenson A. Pellouchoud, Meng-Ju Sher, Sanghee Nah, Yi-Hong Kuo, Yifei Yu, Ann F. Marshall, Linyou Cao, Evan J. Reed, and Aaron M. Lindenberg; ACS Nano, 09/22/14.

Additional Authors: Karel-Alexander N. Duerloo, Lenson A. Pellouchoud, Meng-Ju Sher, Sanghee Nah, Yi-Hong Kuo, Yifei Yu, Ann F. Marshall, Linyou Cao, Evan J. Reed, and Aaron M. Lindenberg

Abstract:

Abstract Image

We report on the dynamical response of single layer transition metal dichalcogenide MoS2 to intense above-bandgap photoexcitation using the nonlinear-optical second order susceptibility as a direct probe of the electronic and structural dynamics. Excitation conditions corresponding to the order of one electron–hole pair per unit cell generate unexpected increases in the second harmonic from monolayer films, occurring on few picosecond time-scales. These large amplitude changes recover on tens of picosecond time-scales and are reversible at megahertz repetition rates with no photoinduced change in lattice symmetry observed despite the extreme excitation conditions.