Semiconducting heterojunctions (HJs), comprised of atomically thin transition metal dichalcogenides (TMDs), have shown great potentials in electronic and optoelectronic applications. Organic/TMD hybrid bilayers hold enhanced pumping efficiency of interfacial excitons, tunable electronic structures and optical properties, and other superior advantages to these inorganic HJs. Here, we report a direct probe of the interfacial electronic structures of a crystalline monolayer (ML) perylene-3, 4, 9, 10-tetracarboxylic-dianhydride (PTCDA)/ML-WSe₂ HJ using scanning tunneling microscopy, photoluminescence, and first-principle calculations. Strong PTCDA/WSe₂ interfacial interactions lead to appreciable hybridization of the WSe₂ conduction band with PTCDA unoccupied states, accompanying with a significant amount of PTCDA-to-WSe₂ charge transfer (by 0.06 e/PTCDA). A type-Ⅱ band alignment was directly determined with a valence band offset of ~ 1.69 eV, and an apparent conduction band offset of ~ 1.57 eV. Moreover, we found that the local stacking geometry at the HJ interface differentiates the hybridized interfacial states.

With the unique properties, layered transition metal dichalcogenide (TMD) and its heterostructures exhibit great potential for applications in electronics. The electrical performance, e.g., contact barrier and resistance to electrodes, of TMD heterostructure devices can be significantly tailored by employing the functional layers, called interlayer engineering. At the interface between different TMD layers, the dangling-bond states normally exist and act as traps against charge carrier flow. In this study, we propose a technique to suppress such carrier trap that uses enhanced interlayer hybridization to saturate dangling-bond states, as demonstrated in a strongly interlayer-coupled monolayer-bilayer PtSe₂ heterostructure. The hybridization between the unsaturated states and the interlayer electronic states of PtSe₂ significantly reduces the depth of carrier traps at the interface, as corroborated by our scanning tunnelling spectroscopic measurements and density functional theory calculations. The suppressed interfacial trap demonstrates that interlayer saturation may offer an efficient way to relay the charge flow at the interface of TMD heterostructures. Thus, this technique provides an effective way for optimizing the interface contact, the crucial issue exists in two-dimensional electronic community.

A topologically mediated synthesis of porous boron nitride aerogel has been experimentally and theoretically investigated for carbon dioxide (CO₂) uptake. Replacement of the carbon atoms in a precursor aerogel of graphene oxide and carbon nanotubes was achieved using an elemental substitution reaction, to obtain a boron and nitrogen framework. The newly prepared BN aerogel possessed a specific surface area of 716.56 m²/g and exhibited an unprecedented twentyfold increase in CO₂ uptake over N₂, adsorbing 100 cc/g at 273 K and 80 cc/g in ambient conditions, as verified by adsorption isotherms via the multipoint Brunauer-Emmett-Teller (BET) method. Density functional theory calculations were performed to give hints on the mechanism of such high selectivity of CO₂ over N₂ adsorption in BN aerogel, which may be due to the interaction between the intrinsic polar nature of B-N bonds and the high quadrupole moment of CO₂ over N₂.

Phosphorus atomic chains, the narrowest nanostructures of black phosphorus (BP), are highly relevant to the in-depth development of BP-based one-dimensional (1D) nano-electronics components. In this study, we report a top-down route for the preparation of phosphorus atomic chains via electron beam sculpturing inside a transmission electron microscope (TEM). The growth and dynamics (i.e., rupture and edge migration) of 1D phosphorus chains are experimentally captured for the first time. Furthermore, the dynamic behavior and associated energetics of the as-formed phosphorus chains are further investigated by density functional theory (DFT) calculations. It is hoped that these 1D BP structures will serve as a novel platform and inspire further exploration of the versatile properties of BP.