Abstract
2-D transition metal dichalcogenides (TMDCs)have great potential in ultra-thin photodetectors. How-ever, the atomically thin thickness leads to weak light absorption, thus hindering their applications. Herein, this work demonstrates that the modification of MoSe2/WSe(2 )heterojunction photodetectors with gold (Au) nanorods can dramatically enhance the photoelectric performance of heterojunction photodetectors. The Au nanorods are integrated into TMDCs heterojunctions of WSe2/MoSe2(Au/WSe2/MoSe2) by a dry-transfer method. The responsivity of its photodetector is dramatically improved from visible to infrared spectral range, with a maximum enhancement of 97-fold at 750 nm and a large enhancement of42-fold at 1100 nm. The enhancement is attributed to the broadband surface plasmon resonance supported by the Au nanorods. Combining TMDCs heterojunction with sur-face plasmon metal nanostructures provides a new strategy for realizing photodetectors with high response in a broad spectral range.