Surface Plasmon‐Enhanced Photodetection in Few Layer MoS2 Phototransistors with Au Nanostructure Arrays

2D Molybdenum disulfide (MoS 2 ) is a promising candidate material for high‐speed and flexible optoelectronic devices, but only with low photoresponsivity. Here, a large enhancement of photocurrent response is obtained by coupling few‐layer MoS 2 with Au plasmonic nanostructure arrays. Au nanoparticles or nanoplates placed onto few‐layer MoS 2 surface can enhance the local optical field in the MoS 2 layer, due to the localized surface plasmon (LSP) resonance. After depositing 4 nm thick Au nanoparticles sparsely onto few‐layer MoS 2 phototransistors, a doubled increase in the photocurrent response is observed. The photocurrent of few‐layer MoS 2 phototransistors exhibits a threefold enhancement with periodic Au nanoarrays. The simulated optical field distribution confirms that light can be trapped and enhanced near the Au nanoplates. These findings offer an avenue for practical applications of high performance MoS 2 ‐based optoelectronic devices or systems in the future.