Direct measurement of key exciton properties: Energy, dynamics, and spatial distribution of the wave function
Artikel i vetenskaplig tidskrift, 2021
Excitons, Coulomb-bound electron–hole pairs, are the fundamental excitations governing the optoelectronic properties of semiconductors. Although optical signatures of excitons have been studied extensively, experimental access to the excitonic wave function itself has been elusive. Using multidimensional photoemission spectroscopy, we present a momentum-, energy-, and time-resolved perspective on excitons in the layered semiconductor WSe2. By tuning the excitation wavelength, we determine the energy–momentum signature of bright exciton formation and its difference from conventional single-particle excited states. The multidimensional data allow to retrieve fundamental exciton properties like the binding energy and the exciton–lattice coupling and to reconstruct the real-space excitonic distribution function via Fourier transform. All quantities are in excellent agreement with microscopic calculations. Our approach provides a full characterization of the exciton properties and is applicable to bright and dark excitons in semiconducting materials, heterostructures, and devices. Key points: The full life cycle of excitons is recorded with time- and angle-resolved photoemission spectroscopy. The real-space distribution of the excitonic wave function is visualized. Direct measurement of the exciton-phonon interaction.
ultrafast dynamics
semiconductors
exciton physics
many-body physics
quasi-particle interactions
condensed matter physics
time-resolved photoemission spectroscopy
Författare
Shuo Dong
Max-Planck-Gesellschaft
Michele Puppin
Max-Planck-Gesellschaft
Ecole Polytechnique Federale de Lausanne (EPFL)
Tommaso Pincelli
Max-Planck-Gesellschaft
Samuel Beaulieu
Max-Planck-Gesellschaft
Dominik Christiansen
Technische Universität Berlin
Hannes Hübener
Max-Planck-Gesellschaft
Christopher W. Nicholson
Max-Planck-Gesellschaft
Université de Fribourg
Rui Patrick Xian
Max-Planck-Gesellschaft
Maciej Dendzik
Kungliga Tekniska Högskolan (KTH)
Max-Planck-Gesellschaft
Yunpei Deng
Max-Planck-Gesellschaft
Paul Scherrer Institut
Yoav William Windsor
Max-Planck-Gesellschaft
M. Selig
Technische Universität Berlin
Ermin Malic
Chalmers, Fysik, Kondenserad materie- och materialteori
Angel Rubio
Max-Planck-Gesellschaft
A. Knorr
Technische Universität Berlin
Martin Wolf
Max-Planck-Gesellschaft
Laurenz Rettig
Max-Planck-Gesellschaft
Ralph Ernstorfer
Max-Planck-Gesellschaft
Natural Sciences
26986248 (eISSN)
Vol. 1 1 e10010Ämneskategorier
Atom- och molekylfysik och optik
Den kondenserade materiens fysik
DOI
10.1002/ntls.10010