Layered two-dimensional (2D) semiconductors, such as MoS(2) and SnS(2), have been receiving intensive attention due to their technological importance for the next-generation electronic/photonic applications. We report a novel approach to the controlled synthesis of thin crystal arrays of SnS(2) at predefined locations on chip by chemical vapor deposition with seed engineering and have demonstrated their application as fast photodetectors with photocurrent response time ∼ 5 μs. This opens a pathway for the large-scale production of layered 2D semiconductor devices, important for applications in integrated nanoelectronic/photonic systems.

Elementary tellurium is currently of great interest as an element with potential promise in nano-technology applications because of the recent discovery regarding its three two-dimensional phases and the existence of Weyl nodes around its Femi level. Here, we report on the unique nano-photonic properties of elemental tellurium particles [Te(0)], as harvest from a culture of a tellurium-oxyanion respiring bacteria. The bacterially-formed nano-crystals prove effective in the photonic applications tested compared to the chemically-formed nano-materials, suggesting a unique and environmentally friendly route of synthesis. Nonlinear optical measurements of this material reveal the strong saturable absorption and nonlinear optical extinctions induced by Mie scattering over broad temporal and wavelength ranges. In both cases, Te-nanoparticles exhibit superior optical nonlinearity compared to graphene. We demonstrate that biological tellurium can be used for a variety of photonic applications which include their proof-of-concept for employment as ultrafast mode-lockers and all-optical switches.

The present work serves as a scalable basis upon which to expand the usage of MWCNT/polymeric nanocomposites into high-conductivity applications.

Nanocarbon-based disordered, conductive, polymeric nanocomposite materials (DCPNs) are increasingly being adopted in applications across the breadth of materials science. DCPNs characteristically exhibit poor electroconductive properties and irreproducibility/ irreversibility in electronic phenomena, due largely to the percolative disordered nature intrinsic to such systems. The authors herein present an alternative approach toward enhancing the thermoresponsivity, repeatability, and reversibility of nanocarbon-based DCPNs in thermometric applications. This is empirically demonstrated using poly(octadecyl acrylate)-graf ted-multiwall carbon nanotubes (PODA-g-MWCNTs) synthesized via reversible addition−fragmentation chain-transfer (RAFT) polymerization. Synthesized PODA-g-MWCNTs exhibit repeatable, nearpyrexia sensitized, switch-like electronic responses across subtle glass transitions characterized by an exceptionally large positive temperature coefficient of resistance values of 7496.53% K −1 ± 3950.58% K −1 at 315.1 K (42.0 °C). This corresponds to a sizable transition rate of 17.39 kΩ K −1 ± 0.49 kΩ K −1 , and recoverable near room temperature resistance values of 246.17 Ω ± 12.19 Ω at 298.2 K (25.1 °C). Near-human body temperature sensitized PODA-g-MWCNTs assembled in this work are promising candidates for wearable temperature sensors and other thermometric applications.