nn0c06311_si_001.pdf (1.39 MB)
Decelerated Hot Carrier Cooling in Graphene via Nondissipative Carrier Injection from MoS2
journal contribution
posted on 2020-08-27, 16:34 authored by Minh Dao Tran, Sung-Gyu Lee, Sunam Jeon, Sung-Tae Kim, Hyun Kim, Van Luan Nguyen, Subash Adhikari, Sungjong Woo, Hee Chul Park, Youngkuk Kim, Ji-Hee Kim, Young Hee LeeOne
key to improve the performance of advanced optoelectronic devices
and energy harvesting in graphene is to understand the predominant
carrier scattering via optical phonons. Nevertheless,
low light absorbance in graphene yields a limited photoexcited carrier
density, hampering the hot carrier effect, which is strongly correlated
to the hot optical phonon bottleneck effect as the energy-loss channel.
Here, by integrating graphene with monolayer MoS2 possessing
stronger light absorbance, we demonstrate an efficient interfacial
hot carrier transfer between graphene and MoS2 in their
heterostructure with a prolonged relaxation time using broadband transient
differential transmittance spectroscopy. We observe that the carrier
relaxation time of graphene in the heterostructure is 4 times slower
than that of bare graphene. This is explained by nondissipative interlayer
transfer from MoS2 to graphene, which is attributed to
the enhanced hot optical phonon bottleneck effect of graphene in the
heterostructure by an increased photoexcited carrier population. A
significant reduction of both amplitude and relaxation time in A-
and B-excitons is another evidence of the interlayer transfer from
MoS2 to graphene. The nondissipative interlayer charge
transfer from MoS2 to graphene is confirmed by density
functional calculations. This provides a different platform to further
study the photoinduced hot carrier effect in graphene heterostructures
for photothermoelectric detectors or hot carrier solar cells.
History
Usage metrics
Categories
Keywords
relaxation timephotoexcited carrier densityphotoexcited carrier populationmonolayer MoS 2phonon bottleneck effectNondissipative Carrier InjectionMoS 2graphenecarrier effectDecelerated Hot Carrier Coolinglight absorbanceheterostructurenondissipative interlayer charge tr...carrier relaxation timenondissipative interlayer transfer
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC