Enhanced-photocurrent in monolayer phototransistor with Au-SiO2 core-shell nanoparticles

Abstract Monolayer Molybdenum disulfide (MoS2) is a typical two-dimensional semiconductor with a direct band-gap, which has promising potential in the application of new optoelectronic devices. Photo-induced carrier separation in ultra-thin channels can induce extremely high performance with low photocurrent. Here, fourfold enhancement of photocurrent is achieved by integrating Au-SiO2 core-shell (Au@SiO2) nanoparticles into the channel of monolayer MoS2 phototransistor, due to the localized surface plasmon (LSP). The theoretic simulation reveals that the enhancement of photocurrent can be attributed to the enhanced localized electric field of “hot spot” at the interface of Au@SiO2 nanoparticles and monolayer MoS2. Besides, the variation of the maximum intensity of the electric field with incident wavelength presents the same tendency with the photocurrent. These results provide a platform for understanding the modulation mechanism of LSP on the optoelectronic performance of the device in the near field.