RESUMO
In this work, a novel hybrid SERS platform incorporating hybrid core-shell (HyCoS) AuPd nanoparticles (NPs) and MoS2 nanoplatelets has been successfully demonstrated for strong surface-enhanced Raman spectroscopy (SERS) enhancement of Rhodamine 6G (R6G). A significantly improved SERS signal of R6G is observed on the hybrid SERS platform by adapting both electromagnetic mechanism (EM) and chemical mechanism (CM) in a single platform. The EM enhancement originates from the unique plasmonic HyCoS AuPd NP template fabricated by the modified droplet epitaxy, which exhibits strong plasmon excitation of hotspots at the nanogaps of metallic NPs and abundant generation of electric fields by localized surface plasmon resonance (LSPR). Superior LSPR results from the coupling of distinctive AuPd core-shell NP and high-density background Au NPs. The CM enhancement is associated with the charge transfer from the MoS2 nanoplatelets to the R6G. The direct contact via mixing approach with optimal mixing ratio can effectively facilitate the charges transfer to the HOMO and LUMO of R6G, leading to the orders of Raman signal amplification. The enhancement factor (EF) for the proposed hybrid platform reaches ~1010 for R6G on the hybrid SERS platform.
RESUMO
A hybrid device scheme is an attractive strategy in the construction of advanced UV photodetectors due to the flexibility in selecting the components and correspondingly improved optoelectronic properties by the cooperation of various components, which cannot be achieved by a single component device. In this work, a novel hybrid UV photodetector (PD) is demonstrated by adapting AuPt alloy hybrid nanoparticles (AHNPs), ZnO quantum dots (QDs), and graphene quantum dots (GQDs), namely, GQD/ZnO/AHNP PD. The optimized device achieves high-end figure-of-merit performance with a responsivity of 2299 mA/W, detectivity of 7.04 × 1010 jones, and external quantum efficiency of 741%. Enhanced photocurrent can be associated with the hot electron generation around the AuPt AHNPs and swift transfer to the conduction band of ZnO QDs. At the same time, the added carrier injection is achieved by a thin layer of GQDs. High density of hotspots and electromagnetic fields are generated by the strong localized surface plasmon resonance (LSPR) by the uniquely designed AuPt AHNPs with the fully alloyed AuPt NPs and adjacent small background Au NPs. The e-field distribution of various NP configurations is systematically investigated with finite-difference time-domain (FDTD) simulations.
