Title: Ultrahigh-Gain Photodetectors Based on Atomically Thin Graphene-MoS2 Heterostructures
Authors: Zhang, Wenjing
Chuu, Chih-Piao
Huang, Jing-Kai
Chen, Chang-Hsiao
Tsai, Meng-Lin
Chang, Yung-Huang
Liang, Chi-Te
Chen, Yu-Ze
Chueh, Yu-Lun
He, Jr-Hau
Chou, Mei-Yin
Li, Lain-Jong
Department of Photonics
Issue Date: 23-Jan-2014
Abstract: Due to its high carrier mobility, broadband absorption, and fast response time, the semi-metallic graphene is attractive for optoelectronics. Another two-dimensional semiconducting material molybdenum disulfide (MoS2) is also known as light-sensitive. Here we show that a large-area and continuous MoS2 monolayer is achievable using a CVD method and graphene is transferable onto MoS2. We demonstrate that a photodetector based on the graphene/MoS2 heterostructure is able to provide a high photogain greater than 108. Our experiments show that the electron-hole pairs are produced in the MoS2 layer after light absorption and subsequently separated across the layers. Contradictory to the expectation based on the conventional built-in electric field model for metal-semiconductor contacts, photoelectrons are injected into the graphene layer rather than trapped in MoS2 due to the presence of a perpendicular effective electric field caused by the combination of the built-in electric field, the applied electrostatic field, and charged impurities or adsorbates, resulting in a tuneable photoresponsivity.
URI: http://dx.doi.org/10.1038/srep03826
ISSN: 2045-2322
DOI: 10.1038/srep03826
Volume: 4
End Page: 
Appears in Collections:Articles

Files in This Item:

  1. 000330045000003.pdf