Tellurium (Te) films with monolayer and few-layer thickness are obtained by molecular beam epitaxy on a graphene/6H-SiC(0001) substrate and investigated by in situ scanning tunneling microscopy and spectroscopy (STM/STS). We reveal that the Te films are composed of parallel-arranged helical Te chains flat-lying on the graphene surface, exposing the (1 × 1) facet of (101̅0) of the bulk crystal. The band gap of Te films increases monotonically with decreasing thickness, reaching the near-infrared band for the monolayer Te. An explicit band bending at the edge between the monolayer Te and graphene substrate is visualized. With the thickness controlled in the atomic scale, Te films show potential applications of electronics and optoelectronics.

Single-walled and multiwalled carbon nanotube blends with polyvinylidene difluoride (and its copolymers) have been characterized. The nanotubes are observed to form a well-dispersed, structurally random nanophase within the fluoropolymer matrix. X-ray analysis coupled with differential scanning calorimetry suggests that the nanophase alters crystal formation within the polymer. For most loadings and nanotube types, the piezoelectric β-polymorph is significantly enhanced over other crystal phases. Solution-cast composite thin films exhibit enhancements in both the pyroelectric response and mechanical transduction over pure polymer. This is interpreted as resulting from the change in crystallinity.

We herein report the functionalization of α-C–H in alcohols through cross-dehydrogenative coupling reactions.

Surface ripple, as an important factor of corrugations in two-dimensional (2D) atomic crystals, plays important roles in determining their mechanical and physical properties. Here, we systematically investigated the strain-engineered rippling structure and manipulation of the rippling domain in monolayer WS2 flakes via atomic force microscopy (AFM). The rippling structure was introduced by the in-plane compression applied through the underlying SiO2/Si substrate during the rapid cooling process of post-growth. The zigzag-orientated rippling domains with three-equivalent directions were visualized by transverse shear microscopy (TSM) and friction force microscopy and further determined via angle-dependent TSM. Furthermore, these rippling domains can be precisely manipulated by controlling the AFM scanning, and various rippling patterns were formed by the AFM lithography. The manipulation mechanisms were phenomenally discussed based on their strain-induced anisotropic mechanical properties, the film–substrate mechanical model, and the dynamic strain-induced anisotropic puckering effects. Our study will be beneficial in understanding and controlling not only the rippling structures but also the rippling-related electronic and optical properties of 2D materials.