Ultrafast non-radiative dynamics of atomically thin MoSe2. Academic Article uri icon

abstract

  • Photo-induced non-radiative energy dissipation is a potential pathway to induce structural-phase transitions in two-dimensional materials. For advancing this field, a quantitative understanding of real-time atomic motion and lattice temperature is required. However, this understanding has been incomplete due to a lack of suitable experimental techniques. Here, we use ultrafast electron diffraction to directly probe the subpicosecond conversion of photoenergy to lattice vibrations in a model bilayered semiconductor, molybdenum diselenide. We find that when creating a high charge carrier density, the energy is efficiently transferred to the lattice within one picosecond. First-principles nonadiabatic quantum molecular dynamics simulations reproduce the observed ultrafast increase in lattice temperature and the corresponding conversion of photoenergy to lattice vibrations. Nonadiabatic quantum simulations further suggest that a softening of vibrational modes in the excited state is involved in efficient and rapid energy transfer between the electronic system and the lattice.

published proceedings

  • Nat Commun

altmetric score

  • 50.58

author list (cited authors)

  • Lin, M., Kochat, V., Krishnamoorthy, A., Bassman Oftelie, L., Weninger, C., Zheng, Q., ... Bergmann, U.

citation count

  • 43

complete list of authors

  • Lin, Ming-Fu||Kochat, Vidya||Krishnamoorthy, Aravind||Bassman Oftelie, Lindsay||Weninger, Clemens||Zheng, Qiang||Zhang, Xiang||Apte, Amey||Tiwary, Chandra Sekhar||Shen, Xiaozhe||Li, Renkai||Kalia, Rajiv||Ajayan, Pulickel||Nakano, Aiichiro||Vashishta, Priya||Shimojo, Fuyuki||Wang, Xijie||Fritz, David M||Bergmann, Uwe

publication date

  • November 2017