Hydrogen in semiconductors and insulators

We describe a first-principles methodology for studying the interactions between hydrogen and materials. In non-metals, isolated hydrogen atoms occur as electrically charged impurities, and this charge has profound effects on the incorporation of hydrogen into the material. We have developed a model that enables us to predict the electrical properties of hydrogen in any material, based on its band alignment on an absolute energy scale. We define the key quantities that describe the interaction between hydrogen and the host materials, and discuss how fundamental knowledge of this type can be applied to hydrogen storage materials. (C) 2006 Elsevier B.V. All rights reserved.