Nanopore/Nanosphere-Induced Optical Enhancement of Monolayer MoS2

Heterostructured transition metal dichalcogenides (TMDs) have received much attention due to their tunable optical and electronic properties. Here, a strategy for facile fabrication of porous anodic alumina (PAA) membrane-supported monolayer molybdenum disulfide (MoS2) is described. PAA is either empty or filled with gold nanoparticles (AuNPs). Such nanopore/nanosphere-supported MoS2 (i.e., PAA-MoS2 and PAA-Au-MoS2) exhibits greatly enhanced optical performances compared with those of silicon wafer-supported MoS2 (i.e., Si/SiO2-MoS2). Notably, 11-fold Raman enhancement, 13-fold photoluminescence enhancement, and 419-fold second-harmonic generation enhancement are achieved in PAA-Au-MoS2. Moreover, the optical enhancement mechanism of this unique structure is proposed. This work provides a platform for the construction of curved/heterostructured TMDs and exploration of their strong light-matter interactions.