This project seeks to design, fabricate, characterize and commercialize very large area, uncooled and radiative hard 4H-SiC VUV detectors capable of near single photon sensing. The detector design and advanced processing technologies combined with the unique material property of 4H-SiC are expected to lead to significant improvements to the performance of large area solid state detectors including much lower noise due to the wide bandgap and substantially improved lifetime due to the greatly increased radiation tolerance in comparison to state-of-the-art based on Si UV technologies. In Phase I, detectors with optical window up to 1cmx1cm will be designed and fabricated. Two batches will be fabricated with different semitransparent metal thicknesses. Concentration will be focused on achieving very low dark current and high quantum efficiency. The fabricated detectors with different optical window sizes will be characterized, including dark current, forward current ideality factor, quantum efficiency. The dominant source and mechanism of the dark current will be investigated to help identify approaches to further reduce the dark current in Phase II which will be concentrating on pushing up the quantum efficiency over a wider spectrum range, further reducing the dark currents, and characterizing reliability and lifetime.