Hydrogen Adsorption on the Indium-Rich Indium Phosphide (001) Surface: A Novel Way to Produce Bridging In−H−In Bonds

Abstract
The indium phosphide (001) surface provides a unique chemical environment for studying the reactivity of hydrogen toward the electron-deficient group IIIA element, indium. Hydrogen adsorption on the In-rich δ(2 × 4) reconstruction produced a neutral, covalently bound bridging indium hydride. Using vibrational spectroscopy and ab initio cluster calculations, two types of bridging hydrides were identified, a (μ-H)In2 and a (μ-H)2In3 “butterfly-like” structure. These structures were formed owing to the large thermodynamic driving force for adsorption of H atoms on solid-state indium dimers.