There has been growing research interest in realizing optoelectronic devices based on the two-dimensional atomically thin semiconductor MoS2 owing to its distinct physical properties that set it apart from conventional semiconductors. However, there is little optical absorption in these extremely thin MoS2 layers, which presents an obstacle toward applying them for use in high-efficiency light-absorbing devices. We synthesized trilayers of MoS2 directly on SiO2/Si nanocone (NC) arrays using chemical vapor deposition and investigated their photodetection characteristics. The photoresponsivity of the MoS2/NC structure was much higher than that of the flat counterpart across the whole visible wavelength range (for example, it was almost an order of magnitude higher at λ = 532 nm). Strongly concentrated light near the surface that originated from a Fabry-Perot interference in the SiO2 thin layers and a Mie-like resonance caused by the Si NCs boosted the optical absorption in MoS2. Our work demonstrates that MoS2/NC structures could provide a useful means to realize high-performance optoelectronic devices.
Bibliographical noteFunding Information:
This study was supported by the National Research Foundation of Korea (2013R1A1A2007951 2014M3C1A3052569, 2014R1A1A1036139, 2016R1D1A1B01009032, and 2016R1D1A1A09917491). B.C. and Y.K. were also supported by the Fundamental Research Program (PNK5290) of the Korean Institute of Materials Science(KIMS).
© 2017 American Chemical Society.
- chemical vapor deposition