P -type conductivity in annealed strontium titanate
In this study, Hall-effect measurements indicate p-type conductivity in bulk, single-crystal strontium titanate (SrTiO3, or STO) samples that were annealed at 1200°C. Room temperature mobilities above 100 cm2/Vs were measured, an order of magnitude higher than those for electrons (5-10 cm2/Vs). Average hole densities were in the 109-1010 cm-3 range, consistent with a deep acceptor.