High-performance photodetector based on hybrid of MoS₂ and reduced graphene oxide

2D materials are a promising new class of materials for next generation optoelectronic devices owing to their appealing optical and electrical properties. Pristine molybdenum disulfide (MoS₂) is widely used in next generation photovoltaic and optoelectronic devices, but its low photo-dark current ratio prevents its use in highly efficient photo detection applications. Here, we decorated crumpled reduced graphene oxide (rGO) particles on a large-area vertically aligned MoS₂ flake network to enhance the performance of the MoS₂-based photodetector by forming multiple nanoscale p-n heterojunctions. The rGO/MoS₂ device exhibited a significantly improved photoresponsivity of ∼2.10 A W^-1 along with a good detectivity of ∼5 × 10¹¹ Jones (Jones = cm Hz^1/2/W) compared to that of the pristine MoS₂ photodetector in ambient atmosphere. Moreover, the rGO/MoS₂ photodetector showed a fast response of ∼18 ms with excellent stability and reproducibility in ambient air even after three months. The high performance of the photodetector is attributed to enhanced photoexcited carrier density and suppressed photo generated electron-hole recombination due to the strong local built-in electric field developed at the rGO/MoS₂ interface. Our results showed that integration of rGO with MoS₂ provides an efficient platform for photo detection applications.