Synergistic Effects of Plasmonic Au Nanoislands on a MoSe₂ Nanoflake/ZnO Nanorod Heterostructure for an Enhanced Broadband Photoresponse

Abstract

We report the enhanced photodetection properties of MoSe2/Au–ZnO vertical heterostructures by probing the synergistic effect of Au nanoislands on the optical response of one-dimensional (1D) vertically standing ZnO nanorods (NRs) and few-layer two-dimensional (2D) MoSe2 nanoflakes, collectively. Plasmonic effects mediated strong light–matter interactions in Au–ZnO hybrids are established through spectroscopic studies. A notable red shift accompanied by a quenched intensity of visible photoluminescence of ZnO NRs supports the energy transfer process from ZnO NRs to Au nanoislands in the plasmonic hybrid. The coupling of defect-originated green emission of ZnO NRs with plasmonic absorption (∼560 nm) and the strategic position of Au nanoislands facilitate easy transfer of plasmonic charge carriers across the heterojunctions and enhance the signal throughout the total operational bandwidth (up to ∼900 nm) of the devices considerably. Such robust devices using 2D/1D mixed-dimensional heterostructures and their direct resonant coupling with strategically integrated 0D plasmonic nanoislands make highly responsive (∼0.43 A/W) broadband photodetectors for future nanophotonic applications.

Synergy between plasmonic nanocavities and random lasing modes: a tool to dequench plasmon quenched fluorophore emission

“…Moreover, the structures in our study are reproducible with the optimized parameters. 64,65 But the emission enhancement obtained in our system is relatively low as compared to the photonic crystal coupled emission platforms. Hence, more work is needed in this direction to obtain higher dequenching of fluorophore emission.…”

“…In this study, the given morphology of ZnO NRs and Au NIs has been chosen owing to the fabrication expertise in obtaining highly reproducible particle shapes, sizes and densities. 64,65 The LSPR band has been chosen so as to obtain varying degrees of spectral overlap for the three different dye emitters. A large dispersion in the shape, size and distribution of Au NIs occurs due to the limitations of the thermal dewetting method, which leads to a wide LSPR band.…”

“…After the cooling of the sample at room temperature, Au NIs decorated over ZnO NRs (AuZnO) were obtained. 64,65…”

“…After the cooling of the sample at room temperature, Au NIs decorated over ZnO NRs (AuZnO) were obtained. 64,65 Synthesis of dye doped polymers. Three dye-doped polymers were used as the gain media to study the random lasing in ZnO and AuZnO samples, namely, pyrromethene (570) doped poly(methyl methacrylate) (PMMA), 4-(dicyanomethylene)-2methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) doped polyvinyl alcohol (PVA) and Nile red doped PVA.…”

Multilayer WSe2/ZnO heterojunctions for self-powered, broadband, and high-speed photodetectors

“…Highperformance broadband photodetectors can be achieved by combining the photodetection performance of 2D TMD materials and ZnO nanostructures. For example, a 2D/1D heterostructure photodetector based on MoSe 2 /ZnO nanorods with a responsivity of 330 mA W −1 at a bias voltage of −2 V has been recently reported [28]. Moreover, a MoSe 2 (n-type)/ZnO (ntype) thin film heterostructure photodetector showed a fast photoresponse of 40 μs [27].…”