Scientific Achievement
The electron mobility in a semiconducting oxide is shown to be dramatically enhanced by the increase of the material’s dielectric constant via screening of defects and impurities. This observation was made in doped crystals of the model ferroelectric KTaxNb1-xO3, in which the temperature at which the dielectric constant peaks, can be continuously tuned via composition.
Significance
Room-temperature electron mobilities in functional oxides are still too low for practical applications, ranging from energy harvesting (photovoltaics, thermoelectrics) to energy storage (battery materials). The observed direct link between dielectric constant and mobility points to a general approach to improving the performance of these technologically relevant oxides.