Doping and hydrogen in wide gap oxides

Abstract The general conditions for doping are considered. Doping by hydrogen is then considered, and whether a single rule separates those oxides in which hydrogen forms only deep states and those in which it acts as a donor. Hydrogen is calculated to act as a shallow donor in oxides ZrO 2 , HfO 2 , SnO 2 , La 2 O 3 , Y 2 O 3 , TiO 2 , SrTiO 3 and LaAlO 3 but it is deep in the oxides SiO 2 , Al 2 O 3 , ZrSiO 4 , HfSiO 4 and SrZrO 3 .