High Mobility in a Stable Transparent Perovskite Oxide

We discovered that La-doped BaSnO3 with the perovskite structure has an unprecedentedly high mobility at room temperature while retaining its optical transparency. In single crystals, the mobility reached 320 cm(2) V-1 s(-1) at a doping level of 8 x 10(19) cm(-3), constituting the highest value among wide-band-gap semiconductors. In epitaxial films, the maximum mobility was 70 cm(2) V-1 s(-1) at a doping level of 4: 4 x 10(20) cm(-3). We also show that resistance of (Ba, La)SnO3 changes little even after a thermal cycle to 530 degrees C in air, pointing to an unusual stability of oxygen atoms and great potential for realizing transparent high-frequency, high-power functional devices. (C) 2012 The Japan Society of Applied Physics