12-02 :: February/March 2012
nanotimes News in Brief
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The band gap is a major factor in determining electrical conductivity in a material and directly determines the upper wavelength limit of light ab- sorption. Thus, achieving wide band gap tunability is highly desirable for developing opto-electronic devices and energy materials.
Using a layer-by-layer growth technique for which Ho Nyung Lee of ORNL (US) earned the Presiden- tial Early Career Award for Scientists and Engineers, Lee and colleagues have achieved a 30% reduction in the band gap of complex metal oxides.
variations in surface patterns, it should be possible to improve even further, he says. The enhanced efficiency could also improve the rate of water pro- duction in plants that produce drinking water from seawater, or even in proposed new solar-power systems that rely on maximizing evaporator (solar collector) surface area and minimizing condenser (heat exchanger) surface area to increase the ove- rall efficiency of solar-energy collection. A similar system could improve heat removal in computer chips, which is often based on internal evaporation and recondensation of a heat-transfer liquid through a device called a heat pipe.
Nenad Miljkovic, Ryan Enright, and Evelyn N. Wang: Effect of Droplet Morphology on Growth Dynamics and Heat Transfer during Condensation on Superhydropho- bic Nanostructured Surfaces, In: ACS Nano, Vol. 6(2012), Issue 6, Pages 1776-1785, DOI:10.1021/nn205052a: http://dx.doi.org/10.1021/nn205052a
http://www.youtube.com/watch?feature=player_ embedded&v=U-aYV0DDuak
ORNL‘s material scientists developed a synthesis strategy for discovering novel complex-oxide thin films for stron- ger solar light absorption. © ORNL
“Our approach to tuning band gaps is based on atomic-scale growth control of complex oxide ma-