TY - JOUR
T1 - Exciton dynamics in monolayer transition metal dichalcogenides [Invited]
AU - Moody, Galan
AU - Schaibley, John
AU - Xu, Xiaodong
N1 - Publisher Copyright:
© 2016 Optical Society of America.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Since the discovery of semiconducting monolayer transition metal dichalcogenides, a variety of experimental and theoretical studies have been carried out seeking to understand the intrinsic exciton population recombination and valley relaxation dynamics. Reports of the exciton decay time range from hundreds of femtoseconds to ten nanoseconds, while the valley depolarization time can exceed one nanosecond. At present, however, a consensus on the microscopic mechanisms governing exciton radiative and non-radiative recombination is lacking. The strong exciton oscillator strength resulting in up to 20% absorption for a single monolayer points to ultrafast radiative recombination. However, the low quantum yield and large variance in the reported lifetimes suggest that non-radiative Auger-type processes obscure the intrinsic exciton radiative lifetime. In either case, the electron-hole exchange interaction plays an important role in the exciton spin and valley dynamics. In this paper, we review the experiments and theory that have led to these conclusions and comment on future experiments that could complement our current understanding.
AB - Since the discovery of semiconducting monolayer transition metal dichalcogenides, a variety of experimental and theoretical studies have been carried out seeking to understand the intrinsic exciton population recombination and valley relaxation dynamics. Reports of the exciton decay time range from hundreds of femtoseconds to ten nanoseconds, while the valley depolarization time can exceed one nanosecond. At present, however, a consensus on the microscopic mechanisms governing exciton radiative and non-radiative recombination is lacking. The strong exciton oscillator strength resulting in up to 20% absorption for a single monolayer points to ultrafast radiative recombination. However, the low quantum yield and large variance in the reported lifetimes suggest that non-radiative Auger-type processes obscure the intrinsic exciton radiative lifetime. In either case, the electron-hole exchange interaction plays an important role in the exciton spin and valley dynamics. In this paper, we review the experiments and theory that have led to these conclusions and comment on future experiments that could complement our current understanding.
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U2 - 10.1364/JOSAB.33.000C39
DO - 10.1364/JOSAB.33.000C39
M3 - Article
AN - SCOPUS:84978198748
SN - 0740-3224
VL - 33
SP - C39-C49
JO - Journal of the Optical Society of America B: Optical Physics
JF - Journal of the Optical Society of America B: Optical Physics
IS - 7
ER -