Hydrogenated barium titanate film based metal-insulator-metal (MIM) systems show high dielectric constant and have therefore been proposed as solid state supercapacitors. Hydrogen was incorporated in the dielectric layer during the low temperature deposition process. An investigation of the electrical properties has revealed that hydrogen contributes to the conduction process as mobile ionic species as well as donor trap levels. (C) 2009 Elsevier B.V. All rights reserved.