Platinum nanoparticle sensitized plasmonic-enhanced broad spectral photodetection in large area vertical-aligned MoS₂ flakes

Abstract

2D MoS2 holds immense potential for electronic and optoelectronic applications due to its unique characteristics. However, the atomic-scale thickness of MoS2 hinders the optical absorbance, thereby limiting its photodetection capability. Vertically-aligned MoS2 (VA-MoS2) has an advantange of strong optical absorption and quick intra-layer transport, offering high speed operation. The coupling of plasmonic metal nanostructure with MoS2 can further enhance the light-matter interaction. Pt/Pd (as opposed to Ag/Au) are more promising to design next-generation nano-plasmonic devices due to their intense interband activity over a broad spectral range. Herein, we report Pt nanoparticle (NPs) enhanced broadband photoresponse in VA-MoS2. The optical absorbance of MoS2 is enhanced after the integration of Pt NPs, with a four-fold enhancement in photocurrent. The formation of Schottky junction at Pt-MoS2 interface inhibits electron transmission, suppressing the dark current and substantially reducing NEP. The plasmonic-enabled photodetector shows enhanced responsivity (432 AW-1, 800 nm) and detectivity (1.85 × 1014 Jones, 5 V) with a low response time (87 ms /84 ms), attributed to faster carrier transport. Additionally, a theoretical approach is adopted to calculate wavelength-dependent responsivity, which matches well with experimental results. These findings offer a facile approach to modulate the performance of next-generation optoelectronic devices for practical applications.

CuBi2O4nanocrystals integrated with polyaniline nanobelt arrays for weak light photomultiplication type photodetector

“…37,41 Dark current can be efficiently suppressed using techniques such as electrical manipulations by ferroelectric, built-in, and gate electric elds. 30,42,43 By combining with other materials, the response spectrum of a photodetector based on hybrid materials could likewise be widened to the infrared region. Poor photoresponsivity can occur from the high exciton binding energy making it difficult to separate and gather e-h pairs.…”

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

“…Arrays of 1D nanostructures like nanocones or nanorods (NRs) and their contribution in a higher photoresponse have been proven to be effective and useful for future transparent and flexible nanodevices. − In this regard, zinc oxide (ZnO) nanostructures are important because of their high band gap, chemical stability, and optical transparency. , Combination of these nanostructures with atomically thin 2D TMDs like MoS 2 , and WS 2 , has been reported to provide improved performance in terms of sensitivity with additional light absorption capability and broadening of the spectral range. On the other hand, the large surface area of 1D or 2D materials and the coupling of their excitonic features with metal nanoparticle (NP)-induced plasmonic interactions have shown promising opportunities in realizing fast and efficient devices. − Metal NPs through localized surface plasmon resonance (LSPR) can trap light on the surface of a material by strongly controlling the absorption and emission spectra and depending on the shape and morphology of the metal NPs, such physical effects can be tuned to a great extent in terms of coupling strength. ,− Integration of stable plasmonic metal NPs like gold (Au) has been especially useful for photovoltaics and broadband photodetection. − However, the fabrication of such mixed-dimensional devices is challenging in terms of growth of thin-layered (2D) materials on top of the large-area vertical (1D) micro/nanostructures. Solution-processed 2D materials can thus be an alternative, wherein they can be simply spin- or dip-coated over the preferred thin film/substrate at a large scale.…”

Pt Nanoparticles on Vertically Aligned Large-Area MoS2Flakes for Selective H2Sensing at Room Temperature

“…36 The PL emission intensity of MoS 2 is enormously reduced by 72% after incorporation of Pt NPs, suggesting PL quenching attributed to the strong charge transfer between Pt NPs and MoS 2 . 34 Here, PL quenching in Pt@MoS 2 infers the doping by Pt NPs ascribed to the change in the electronic structure of the hybrid system. The Fermi levels of VA-MoS 2 and Pt are 4.83 and 5.6 eV.…”

“…Nonetheless, the intensity of both the Raman vibrational modes of MoS 2 is drastically enhanced. The surface-enhanced Raman scattering (SERS) in MoS 2 is ascribed to the augmented electromagnetic field intensity induced from localized surface plasmon resonance of Pt NPs. , The PL spectra of VA-MoS 2 exhibit two characteristic emission peaks at 1.82 and 1.94 eV corresponding to A and B excitons, respectively, as shown in Figure c. The A exciton peak is associated with a direct bandgap transition, while the B exciton peak arises due to interlayer interactions and spin–orbit coupling in the valence band of MoS 2 .…”