FIELD

Provided herein are core-shell heterostructures comprising a metal nanoparticle core and a transition metal dichalcogenide (TMD) shell, and methods of preparation and use thereof. In particular embodiments, the core-shell heterostructures described herein are synthesized by direct growth of a monolayer or multilayer fullerene-like TMD shell on a metal (e.g., noble metal) nanoparticle core, exhibit unique Raman scattering and photoluminescence characteristics, and are useful, for example, in plasmonic hot electron enhanced optics and optoelectronics.

BACKGROUND

There exists a need to develop devices and materials for optoelectronics, optical imaging, and other energy-environmental applications.

SUMMARY

Provided herein are core-shell heterostructures comprising a metal (e.g., noble metal) nanoparticle core and a transition metal dichalcogenide (TMD) shell, and methods of preparation and use thereof. In particular embodiments, the core-shell heterostructures described herein are synthesized by direct growth of a monolayer or multilayer fullerene-like TMD shell on a metal (e.g., noble metal) nanoparticle core, exhibit unique Raman scattering and photoluminescence characteristics, and are useful, for example, in plasmonic hot electron enhanced optics and optoelectronics.

In some embodiments, provided herein are compositions comprising a metal (e.g., noble metal) core and monolayer or multilayer transition metal dichalcogenide (TMD) shell (e.g., Au@MoS2core-shell heterostructures comprising Au nanoparticles encapsulated within a MoS2shell). In some embodiments, the metal core comprises a noble metal and is a single phase or alloy of gold (Au), silver (Ag), platinum (Pt), Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Iridium (Ir), and/or Osmium (Os). In some embodiments, the metal core comprises a transition metal such as zinc (Zn), cadmium (Cd), iron (Fe), nickel (Ni), titanium (Ti), scandium (Sc), chromium (Cr), cobalt (Co), etc. In some embodiments, a metal core comprise noble and transition metals or alloys thereof. In some embodiments, the TMD shell is a monolayer or multilayer fullerene-like shell. In some embodiments, the TMD is a single or composite semiconductor of the type MX2, with M a transition metal atom (Mo, W, etc.) and X a chalcogen atom (S, Se, or Te). Typical examples of TMD include molybdenum disulfide (MoS2), tungsten disulfide (WS2), rhenium disulfide (ReS2), molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), and/or Molybdenum ditelluride (MoTe2). In some embodiments, the TMD shell comprises 1-50 layers (e.g., 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, or ranges therebetween). In some embodiments, the noble metal nanoparticles are 5-200 nm in diameter (e.g., 5, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200 or ranges therebetween). In some embodiments, the MoS2shell is 0.65-32.5 nm thick (e.g., 0.65, 1.95, 3.25, 4.55, 5.85, 7.15, 8.45, 9.75, 11.05, 12.35, 13.65, 14.95, 16.25, 17.55, 18.85, 20.15, 21.45, 22.75, 24.05, 25.35, 26.65, 27.95, 29.25, 30.55, 31.85, 32.5 or ranges therebetween).

In some embodiments, provided herein are methods for preparing the core-shell heterostructures described herein comprising directly growing a monolayer or multilayer TMD shell on a metal (e.g., noble metal) nanoparticle core. In some embodiments, the multilayer TMD shell is grown by chemical vapor deposition. In some embodiments, metal (e.g., noble metal) nanoparticles are formed by coating metal (e.g., noble metal) film onto a silicon (Si) substrate via galvanic deposition or physical evaporation followed by high-temperature annealing. In some embodiments, the metal (e.g., noble metal) nanoparticles are commercially available metal (e.g., noble metal) nanoparticles. In some embodiments, a metal (e.g., noble metal) nanoparticle-coated Si substrate (e.g., Au nanoparticle-coated Si substrate) is placed in a tube furnace and transition metal oxide and sulfur powder is carried over the substrate to form TMD shells on the nanoparticles.

In some embodiments, provided herein are photodetector devices comprising the metal@TMD (e.g., noble-metal@TMD (e.g., Au@MoS2, etc.), etc.) core-shell heterostructures described herein.

In some embodiments, provided herein are compositions comprising the core-shell heterostructures described herein, patterned onto a substrate. In some embodiments, the noble metal (e.g., Au, etc.) nanoparticles encapsulated within a TMD (e.g., MoS2) shell are deposited onto the substrate using a standard photolithography process.

In some embodiments, provided herein is the use of the metal@TMD (e.g., noble-metal@TMD (e.g., Au@MoS2, etc.), etc.) core-shell heterostructures described herein in plasmonic hot electron enhanced optics and/or optoelectronics.

