The cover photo of July 2019 issue is dedicated to the 41st anniversary of the first reported synthetic approach of dendritic hyperbranched structure. The cover photo adopted from the Valer et al., where they reported the preparation of dendritic hyperbranched copolymers based on bis(hydroxyl methyl) propionic acid polyester and studied the architecture - behavior - properties relationship. Dendritic structures are known for their perfect chemical definition, highly dense structure, and a well-defined number of surface functionalities. The soft multifunctional modifications could be compliant to valuable flexibility for embedding different chemical moieties on the surface either within the structure or at the core.
Effect of parasitic polytypes on ballistic electron transport in chemical vapor deposition grown 6H-SiC epitaxial layers
Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva, 8410501 Israel
Adv. Mater. Lett., 2019, 10 (7), pp 465-469
Publication Date (Web): Jan 14, 2019
Copyright © 2019 VBRI Press
Growth of epitaxial layers is required for most of today’s devices. Epilayer growth is commonly carried out under conditions less optimal than those of bulk growth. In materials having multiple stable polytypes, such as SiC, it may facilitate concurrent nucleation of undesired polytypes. Using ballistic electron emission spectroscopy, we have repeatedly encountered a spectral feature in chemical vapor deposition (CVD) grown 6H-SiC layers that was absent in spectra of bulk material. This feature is suggested to belong to 4H-SiC inclusions. The presence of a concurrent Schottky barrier in our CVD epilayers coincides with an observation of a lower Fermi level pinning position compared with bulk material. © VBRI Press.
Silicon carbide, 6H-SiC, polytypes.