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An effective way of addressing the need for an improved culture of safety in research-intensive science departments is described, which involves enabling leadership by graduate student and postdoctoral associate laboratory safety officers (LSOs). In partnership with The Dow Chemical Company, LSOs from the Departments of Chemistry and Chemical Engineering and Materials Science at the University of Minnesota formed a Joint Safety Team. With helpful input from Dow, the team has played a key role in improving the culture and practice of safety in both departments, providing support for use of this model for inculcating safety as a core value and an integral part of academic life.

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Electrical conductivities of thin films of silicon nanocrystals (4-6 nm) exhibit high sensitivity to water vapor. Specifically, water adsorption on the surface of silicon nanocrystal (NC) films increases their electrical conductivity by a factor of four at room temperature and an order of magnitude at 175 K. The increase in conductivity is reversible and can manifest as peaks or hysteresis loops in temperature-dependent conductivity measurements even when the measurements are conducted under vacuum at 10-5 Torr and in the presence of only residual amounts of water vapor. Hydrogenterminated silicon nanocrystals are easily oxidized to form submonolayer to monolayer of chemically bound oxygen on their surfaces when annealed at 300°C in a glovebox with 0.1 ppm of water vapor. Annealing under vacuum at 300°C retains H-passivation without oxidation. The electrical conductivity of films made from hydrogen-terminated silicon nanocrystals is 200 times higher than the electrical conductivity of films made from silicon nanocrystals with a monolayer of chemically bound oxygen. However, the conductivities of both types of films increase upon adsorption of water on the nanocrystal surfaces. These findings underscore the importance of controlling silicon nanocrystal surfaces in determining the electrical properties of their thin films.