Printable Transfer-Free and Wafer-Size MoS2/Graphene van der Waals Heterostructures for High-Performance Photodetection.
Two-dimensional (2D) MoS2/graphene van der Waals heterostructures integrate the superior light-solid interaction in MoS2and charge mobility in graphene for high-performance optoelectronic devices. Key to the device performance lies in a clean MoS2/graphene interface to facilitate efficient transfer of photogenerated charges. Here, we report a printable and transfer-free process for fabrication of wafer-size MoS2/graphene van der Waals heterostructures obtained using a metal-free-grown graphene, followed by low-temperature growth of MoS2from the printed thin film of ammonium thiomolybdate on graphene. The photodetectors based on the transfer-free MoS2/graphene heterostructures exhibit extraordinary short photoresponse rise/decay times of 20/30 ms, which are significantly faster than those of the previously reported MoS2/transferred-graphene photodetectors (0.28-1.5 s). In addition, a high photoresponsivity of up to 835 mA/W was observed in the visible spectrum on such transfer-free MoS2/graphene heterostructures, which is much higher than that of the reported photodetectors based on the exfoliated layered MoS2(0.42 mA/W), the graphene (6.1 mA/W), and transfer-free MoS2/graphene/SiC heterostructures (∼40 mA/W). The enhanced performance is attributed to the clean interface on the transfer-free MoS2/graphene heterostructures. This printable and transfer-free process paves the way for large-scale commercial applications of the emerging 2D heterostructures in optoelectronics and sensors.
Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas 66045, United States.
Qingfeng
http://orcid.org/0000-0003-2492-8092
Q
Liu
Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas 66045, United States.
Brent
B
Cook
Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas 66045, United States.
Maogang
http://orcid.org/0000-0002-2031-781X
M
Gong
Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas 66045, United States.
Youpin
http://orcid.org/0000-0002-2155-9511
Y
Gong
Department of Energy's National Security Campus , Kansas City, Missouri 64147, United States.
Dan
D
Ewing
Department of Energy's National Security Campus , Kansas City, Missouri 64147, United States.
Matthew
M
Casper
Department of Energy's National Security Campus , Kansas City, Missouri 64147, United States.
Alex
A
Stramel
Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas 66045, United States.
Judy
J
Wu
MoS2; graphene; heterostructures; photodetectors; printable; transfer-free