Search

The optical properties of two species of localized interlayer excitons in a van der Waals heterostructure are shown to depend on their spin–valley–layer configuration, enabling the identification of the moiré atomic registry and offering insights for engineering quantum states in two-dimensional materials.

Here, the authors discover the ground and excited state interlayer excitons in bi- and tri-layer 2H-MoSe₂ crystals which exhibit electric-field-driven hybridisation with the intralayer A excitons, showing distinct spin, layer and valley characteristics.

Heterostructures of transition metal dichalcogenides are known to simulate the triangular-lattice Hubbard model. Now, by combining a monolayer and bilayer of different materials, this idea is extended to multi-orbital Hubbard models.

Wide- and narrow-bandgap semiconductor nanostructures were monolithically integrated on graphene layers by direct heteroepitaxial growth. The structural, optical, and electrical characteristics of the hybrid nanostructures were investigated. Furthermore, dual-wavelength photodetectors sensitive to both ultraviolet and mid-infrared wavelengths were fabricated using the hybrid nanostructures.

We demonstrate intracellular GaN microrod lasers for cell labeling applications. GaN microrods show excellent lasing signals under intracellular conditions with a low lasing threshold (~270 kW/cm²). The lasing spectra from individual intracellular microrods are distinguishable because each GaN microrod has different lasing peak wavelength, mode spacings, and relative PL intensities. This result suggests that GaN microrods can be candidates for cell labeling applications.

Moiré-trapped interlayer excitons in a transition metal dichalcogenide heterobilayer serve as a sensitive optical probe of carrier filling in their immediate environment to characterize the doping of the moiré superlattice.

We demonstrate the growth of high-quality GaN films with flat surface and uniform morphology on large-scale polycrystalline chemical vapor-deposited graphene films. The films exhibit stimulated emission even at room temperature, a highly c-axis-oriented crystal structure, and a preferred in-plane orientation. Furthermore, the GaN films grown on the graphene films can be used for fabrication of blue and green light-emitting diodes.

A novel technique is demonstrated for the fabrication of flexible and highly sensitive 1D piezoelectric pressure sensors containing ZnO nanotube arrays grown on 2D graphene layers. Due to the morphology-controlled tunable sensitivity, ultra-small size, and capability of detecting extremely low pressures, the sensors are able to efficiently detect human breath and pulse.

Architectured ZnO nanostructures were grown by van der Waals (vdW) heteroepitaxy on hexagonal BN (hBN) layers with artificially patterned atomic ledges. Electron microscopic and theoretical computational analyses presented non-covalent epitaxial features of domain-aligned incommensurate ZnO/hBN heterostructure. The vdW epitaxial ZnO/hBN heterostructures exhibited excellent electrical insulation of hBN, and were applied to fabricate the ultraviolet photodetector devices, as an example of functional optoelectronic device applications.