H-Radical Reactive Infrared Laser Deposition of LiH: A Method for Growing High-Quality Metal Hydride Epitaxial Films

Abstract

We present a new film growth method designed specifically for growing metal hydride thin films that we name “H-radical reactive infrared laser deposition”. This approach leverages hydrogen radicals (H·) to achieve rapid and complete metal hydrogenation, leading to high-purity hydride phases. We demonstrate the effectiveness of this method through the growth of LiH epitaxial thin films, where the H· supply eliminates Li precipitates and enhances crystallinity. Additionally, the use of an infrared laser minimizes film–substrate reactions, reducing the level of impurity formation. To explore the material tunability of this method, we successfully controlled film orientation and achieved Mg doping in LiH. Our findings establish H-radical reactive infrared laser deposition as a promising method for fabricating high-quality metal hydride thin films with tailored properties.