Gallium Nitride Grown on Graphene: Nitride semiconductor materials used in light-emitting diodes and lasers are usually grown on single-crystal sapphire substrates with intermediate buffer layers. Instead, Chung et al. (p. 655 ) used graphene as a substrate for gallium nitride growth and found that nucleation of the gallium nitride layers was enhanced by first depositing zinc oxide, which grew as vertical nanowalls on the graphene. The gallium nitride layers displayed strong photo- and electroluminescence and, even better, the layers could be transferred to flexible substrates such as plastic.

A single thin-film transistor senses, amplifies, and multiplexes force to sense slip and close the loop in robotic gripping.

We report the growth of high-quality GaN films on large-size graphene films for visible light-emitting diodes (LEDs). The graphene films were synthesized by chemical vapor deposition and then transferred onto amorphous silica (SiO₂) substrates that do not have an epitaxial relationship with GaN. Before growing the high-quality GaN thin films, ZnO nanowalls were grown on the graphene films as an intermediate layer. The structural and optical characteristics of the GaN films were investigated, and the films exhibited stimulated emission even at room temperature, a highly c-axis-oriented crystal structure, and a preferred in-plane orientation. Visible LEDs that emitted strong electroluminescence under room illumination were fabricated using the GaN thin films.