Jawad Ul Hassan

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The elimination of defects from SiC has facilitated its move to the forefront of the optoelectronics and power-electronics industries. Nonetheless, because certain SiC defects have electronic states with sharp optical and spin transitions, they are increasingly recognized as a platform for quantum information and nanoscale sensing. Here, we show that(More)
We report a simple, handy and affordable optical approach for precise number-oflayers determination of graphene on SiC based on monitoring the power of the laser beam reflected from the sample (reflectance mapping) in a slightly modified micro-Raman setup. Reflectance mapping is compatible with simultaneous Raman mapping. We find experimentally that the(More)
Graphene grown on C-face SiC substrates using two procedures, high and low growth temperature and different ambients, was investigated using Low Energy Electron Microscopy (LEEM), X-ray Photo Electron Electron Microscopy (XPEEM), selected area Low Energy Electron Diffraction (μ-LEED) and selected area Photo Electron Spectroscopy (μ-PES). Both types of(More)
4H-SiC epilayers grown by standard and chlorinated chemistry were analyzed for their minority carrier lifetime and deep level recombination centers using time resolved photoluminescence (TRPL) and standard deep level transient spectroscopy (DLTS). Next to the well-known Z1/2 deep level a second effective lifetime killer, RB1 (activation energy 1.05 eV,(More)
The optical properties of isotope-pure 28 Si 12 C, natural SiC and enriched with 13 C isotope samples of the 4H polytype are studied by means of Raman and photoluminescence spectroscopies. The phonon energies of the Raman active phonons at the  point and the phonons at the M point of the Brillouin zone are experimentally determined. The excitonic bandgaps(More)
David J. Christle, Paul V. Klimov, Charles F. de las Casas, Krisztián Szász, Viktor Ivády, Valdas Jokubavicius, Jawad Ul Hassan, Mikael Syväjärvi, William F. Koehl, Takeshi Ohshima, Nguyen T. Son, Erik Janzén, Ádám Gali, and David D. Awschalom Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA Wigner Research Centre for(More)
Abstract- 4H-SiC PiN diodes have been manufactured on a Norstel epitaxied P+ZN/N* substrate with a combination of Mesa and JTE as edge termination. A breakdown voltage of 3.3 kV has been measured at lmuA regardless the active area (0.16 and 2.56 mm<sup>2</sup>). A differential on-resistance of 1.7 mOmega.cm<sup>2</sup> was extracted at 15A-25degC. The(More)
SiC epitaxial growth using the Chemical Vapour Deposition (CVD) technique on nominally on-axis substrate is presented. Both standard and chloride-based chemistry have been used with the aim to obtain high quality layers suitable for device fabrication. Both homoepitaxy (4H on 4H) and heteroepitaxy (3C on hexagonal substrate) are addressed.
We report on the growth of 4H-SiC epitaxial layer on Si-face polished nominally on-axis 2” full wafer, using Hot-Wall CVD epitaxy. The polytype stability has been maintained over the larger part of the wafer, but 3C inclusions have not been possible to avoid. Special attention has given to the mechanism of generation and propagation of 3C polytype in 4H-SiC(More)