Real-time solid-state neutron detectors have been fabricated from semiconducting boron-carbon alloys, deposited by plasma-enhanced chemical vapor deposition. Single neutrons were detected and signals induced by gamma rays were determined to be insignificant. The source gas closo-1,2-dicarbadodecaborane ͑ortho-carborane͒ was used to fabricate the boron-carbon alloys with only the natural isotopic abundance of 10 B. Devices made of thicker boron-carbon alloy layers enriched in 10 B could lead to increased detection efficiency and active diodes could use the inherent micron scale spatial resolution, increasing the range of possible applications.

Adenwalla, Shireen; Welsch, P.; Harken, A.; Brand, Jennifer I.; Sezer, A.; and Robertson, Brian W., "Boron carbide/n-silicon carbide heterojunction diodes" (2001). Faculty Publications from Nebraska Center for Materials and Nanoscience. 85.

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We report on the evolution of the polaron and phonon mode properties in amorphous tungsten oxide thin films measured by spectroscopic ellipsometry in the infrared to ultraviolet spectral regions as a function of the intercalated proton density. A parametric physical model dielectric function is presented, which excellently describes the ellipsometry data over a large intercalated charge-density range. Upon increased amounts of intercalated charge we observe a strong increase in the polaron absorption in the visible spectral range, a decrease in the infrared W-O bond polarity, and an increase in the W = O bond polarity. Our findings support the oxygen-extraction model as the polaron formation mechanism in tungsten oxide in agreement with previous theoretical works based on first-principles pseudopotential calculations. We discuss and suggest polaron formation by oxygen-related defect generation as origin for the coloration mechanism in tungsten oxide. We further discuss possible evidence for very large effective mass of the polarons within the insulator-to-metal transition regime.

Boron carbides fabricated via plasma enhanced chemical vapour deposition from different isomeric source compounds with the same C2B10H12 closo-icosahedral structure result in materials with very different direct (optical) band gaps. This provides compelling evidence for the existence of multiple polytypes of C2B10 boron carbide and is consistent with electron diffraction results.