TY - JOUR
T1 - Observation of 2D semiconductor P-type dark-exciton lifetime using two-photon ultrafast spectroscopy
AU - Panna, Dmitry
AU - Balasubramanian, Krishna
AU - Khatei, Jayakrishna
AU - Rybak, Leonid
AU - Slobodkin, Yevgeny
AU - Steinberg, Hadar
AU - Hayat, Alex
N1 - Publisher Copyright:
© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
PY - 2019
Y1 - 2019
N2 - We report direct measurements of intrinsic lifetimes of P-type dark-excitons in MoS2 monolayers. Using sub-gap excitation, we demonstrate two-photon excited direct population of P-type dark excitons, observe their scattering to bright states and decay with femtosecond resolution. In contrast to one-photon excitation schemes, non-monotonic density variation in bright exciton population observed under two-photon excitation shows the indirect nature of its population and competing decay pathways. Detailed modeling of different recombination pathways of bright and dark excitons allows experimental measurement of 2P dark → 1S bright exciton scattering rates. These insights into the dark states in a MoS2 monolayer pave the way for novel devices such as quantum memories and computing.
AB - We report direct measurements of intrinsic lifetimes of P-type dark-excitons in MoS2 monolayers. Using sub-gap excitation, we demonstrate two-photon excited direct population of P-type dark excitons, observe their scattering to bright states and decay with femtosecond resolution. In contrast to one-photon excitation schemes, non-monotonic density variation in bright exciton population observed under two-photon excitation shows the indirect nature of its population and competing decay pathways. Detailed modeling of different recombination pathways of bright and dark excitons allows experimental measurement of 2P dark → 1S bright exciton scattering rates. These insights into the dark states in a MoS2 monolayer pave the way for novel devices such as quantum memories and computing.
UR - http://www.scopus.com/inward/record.url?scp=85075267256&partnerID=8YFLogxK
U2 - 10.1364/OE.27.033427
DO - 10.1364/OE.27.033427
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C2 - 31878412
AN - SCOPUS:85075267256
SN - 1094-4087
VL - 27
SP - 33427
EP - 33435
JO - Optics Express
JF - Optics Express
IS - 23
ER -