Horizontal and vertical stacked Ag/MoS2 nanostructure enabled excellent carrier mobility and optoelectronic properties

Abstract

Amongst 2D materials, MoS2 with highly exposed atomic edges and large specific surface area are considered potentially strong candidates for optoelectronic devices such as photogenerated electron transport layer, saturated/reverse saturated light absorber. With these prospects in mind, doped nanohybrid system was employed as a “accelerator” for problems related to conductivity and field emission. Herein, the horizontal-vertical stacked Ag/MoS2 films including horizontal nanolayer and vertical nanosheets (NSs) was firstly presented, which exhibit excellent carrier mobility and luminescence characteristics. We have confirmed that the morphology of the Ag/MoS2 NSs (including microworm-like, worm-like, and sheet-like shape), Ag content, micro strain and crystallinity can be adjusted under the different substrate temperature. Base on anisotropy bonding and ultrafast chemical conversion effect of MoS2, the cross-layer diffusion of sputtered atoms is suppressed, thereby the subsequent deposited atoms preferring to diffuse along the van der Waals gap. The efficient light-matter interaction and surface plasmon resonance (SPR) effect is introduced by the abundant exposed S-edges of horizontal-vertical stacked Ag-MoS2 nanostructure, which lead to excellent Raman signal and linear absorption characteristic. The carrier mobility and concentration of Ag/MoS2 NSs with excellent electrical behavior has reached 4480 cm2 V-1S-1 and 3.272 × 1018 cm−2, which can be regarded as the unique ohmic contact and the electron injection effect. Further, the luminescence performance (visible light region) of horizontal-vertical stacked Ag/MoS2-350 °C NSs is 2.5 times higher than that of the original MoS2 NSs, which is dominated by the hot electron injection effect. Importantly, the carrier relaxation time guided by the nonradiative recombination behavior of Ag/MoS2-350 °C NSs was not significantly changed by the incorporation of Ag nanoparticles. The above phenomenon implies that the hot electron injection effect mainly promotes the photoluminescence behavior induced by radiative recombination. The homogeneous and controllable Ag/MoS2 NSs exhibits excellent multiple optoelectronic properties, which can provide a valuable reference strategy for the application of optoelectronic nano-film materials.