Broad-Band Photocurrent Enhancement in MoS 2 Layers Directly Grown on Light-Trapping Si Nanocone Arrays

There has been growing research interest in realizing optoelectronic devices based on the two-dimensional atomically thin semiconductor MoS owing to its distinct physical properties that set it apart from conventional semiconductors. However, there is little optical absorption in these extremely thin MoS layers, which presents an obstacle toward applying them for use in high-efficiency light-absorbing devices. We synthesized trilayers of MoS directly on SiO /Si nanocone (NC) arrays using chemical vapor deposition and investigated their photodetection characteristics. The photoresponsivity of the MoS /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 SiO thin layers and a Mie-like resonance caused by the Si NCs boosted the optical absorption in MoS . Our work demonstrates that MoS /NC structures could provide a useful means to realize high-performance optoelectronic devices.