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Ultrafast response of spontaneous photovoltaic effect in 3R-MoS(2)–based heterostructures

Rhombohedrally stacked MoS(2) has been shown to exhibit spontaneous polarization down to the bilayer limit and can sustain a strong depolarization field when sandwiched between graphene. Such a field gives rise to a spontaneous photovoltaic effect without needing any p-n junction. In this work, we s...

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Detalles Bibliográficos
Autores principales: Wu, Jingda, Yang, Dongyang, Liang, Jing, Werner, Max, Ostroumov, Evgeny, Xiao, Yunhuan, Watanabe, Kenji, Taniguchi, Takashi, Dadap, Jerry I., Jones, David, Ye, Ziliang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9757740/
https://www.ncbi.nlm.nih.gov/pubmed/36525495
http://dx.doi.org/10.1126/sciadv.ade3759
Descripción
Sumario:Rhombohedrally stacked MoS(2) has been shown to exhibit spontaneous polarization down to the bilayer limit and can sustain a strong depolarization field when sandwiched between graphene. Such a field gives rise to a spontaneous photovoltaic effect without needing any p-n junction. In this work, we show that the photovoltaic effect has an external quantum efficiency of 10% for devices with only two atomic layers of MoS(2) at low temperatures, and identify a picosecond-fast photocurrent response, which translates to an intrinsic device bandwidth at ∼100-GHz level. To this end, we have developed a nondegenerate pump-probe photocurrent spectroscopy technique to deconvolute the thermal and charge-transfer processes, thus successfully revealing the multicomponent nature of the photocurrent dynamics. The fast component approaches the limit of the charge-transfer speed at the graphene-MoS(2) interface. The remarkable efficiency and ultrafast photoresponse in the graphene-3R-MoS(2) devices support the use of ferroelectric van der Waals materials for future high-performance optoelectronic applications.