Emergent charge order in pressurized kagome superconductor CsVSb.

The discovery of several electronic orders in kagome superconductors AVSb (A means K, Rb, Cs) provides a promising platform for exploring unprecedented emergent physics. Under moderate pressure (<2.2 GPa), the triple-Q charge density wave (CDW) order is monotonically suppressed by pressure, while the superconductivity shows a two-dome-like behaviour, suggesting an unusual interplay between superconductivity and CDW order.

Charge-density-wave-driven electronic nematicity in a kagome superconductor.

Electronic nematicity, in which rotational symmetry is spontaneously broken by electronic degrees of freedom, has been demonstrated as a ubiquitous phenomenon in correlated quantum fluids including high-temperature superconductors and quantum Hall systems. Notably, the electronic nematicity in high-temperature superconductors exhibits an intriguing entanglement with superconductivity, generating complicated superconducting pairing and intertwined electronic orders. Recently, an unusual competition between superconductivity and a charge-density-wave (CDW) order has been found in the AVSb (A = K, Rb, Cs) family with two-dimensional vanadium kagome nets.

PbI-MoS Heterojunction: van der Waals Epitaxial Growth and Energy Band Alignment.

van der Waals (vdW) epitaxy offers a promising strategy without lattice and processing constraints to prepare atomically clean and electronically sharp interfaces for fundamental studies and electronic device demonstrations. Herein, PbI was thermally deposited at high-vacuum conditions onto CVD-grown monolayer MoS flakes in a vdW epitaxial manner to form 3D-2D heterojunctions, which are promising for vdW epitaxial growth of perovskite films. X-ray diffraction, X-ray photoemission spectroscopy, Raman, and atomic force microscopy measurements reveal the structural properties of the high-quality heterojunctions.

A homogeneous p-n junction diode by selective doping of few layer MoSe using ultraviolet ozone for high-performance photovoltaic devices.

The realization of p-n homojunctions, which can be achieved via spatially controlled carrier-type modulation, remains a challenge for two-dimensional transition metal dichalcogenides. Here, we report an effective method to tune intrinsic n-type few-layer MoSe to p-type through controlling precisely the ultraviolet-ozone treatment time, which can be attributed to the surface charge transfer from the underlying MoSe to MoO (x < 3). The resulting hole mobility and concentration are ∼20.