Improved room temperature electron mobility in self-buffered anatase TiO2 epitaxial thin film grown at low temperature

TiO2(001) epitaxial thin films were grown on LaAlO3(001) substrate self-buffered with 5-monolayer-thick insulating TiO2 by pulsed laser deposition. The use of self-buffer layer enabled the layer-by-layer growth down to 200 degrees C resulting in the decreased surface roughness. The carrier density of self-buffered films was controlled as a function of oxygen pressure during the growth within a range of 10(19)cm(-3). The electron mobility at 300 K of self-buffered film grown at the optimal condition was improved to be 18.6 cm(2).V-1.s(-1) in comparison with that of non-buffered TiO2 thin film <5 cm(2).V-1.s(-1). (C) 2014 The Japan Society of Applied Physics