MOVPE Growth of GaN via Graphene Layers on GaN/Sapphire Templates.

The remote epitaxy of GaN epilayers on GaN/sapphire templates was studied by using different graphene interlayer types. Monolayer, bilayer, double-stack of monolayer, and triple-stack of monolayer graphenes were transferred onto GaN/sapphire templates using a wet transfer technique. The quality of the graphene interlayers was examined by Raman spectroscopy. The impact of the interlayer type on GaN nucleation was analyzed by scanning electron microscopy. The graphene interface and structural quality of GaN epilayers were studied by transmission electron microscopy and X-ray diffraction, respectively. The influence of the graphene interlayer type is discussed in terms of the differences between remote epitaxy and van der Waals epitaxy. The successful exfoliation of GaN membrane is demonstrated.

One small step in synthesis, a big leap in charge mobility: diphenylethenyl substituted triphenylamines.

Star-shaped charge transporting materials with a triphenylamine core and a varying number of diphenylethenyl sidearms, obtained using a one step synthesis procedure from commercially available and relatively inexpensive starting materials and possessing comparatively high hole drift mobility (up to 0.017 cm(2) V(-1) s(-1)), are reported.