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Chemical, electrical, and optical measurements were performed on n- and p-type β-silicon carbide crystals grown from pure or doped carbon-saturated silicon melts. Pure, transparent yellow crystals showed no detectable impurities and had carrier concentrations in the range of 1016 cm−3. Extensive twinning was observed. Uncorrected electron mobilities of 700–1000 cm2/V·sec were measured at room temperature. Intense injection electroluminescence, peaking at 2.28 eV and 2.0 eV, was observed in many diodes. Strong photoluminescence was observed in aluminum-doped crystals at 77°K and at room temperature when irradiated with uv light.

High-resolution simulations of field emission electron sources have been made using the electron optics program EGN2. Electron emission distributions are made using the Fowler-Nordhcim equation. Mesh resolution in the range of 1 5 X is required to adequately model surface details that can result in emission currents in I lie range found experimentally. A typical problem starts with mechanical details with dimensions of