Similarity of electronic structure and optical properties of Mg₂ NiH₄ and Si

Using the first-principles calculations a comparative analysis of electronic structure and optical properties of crystalline Si with cubic Mg ₂NiH₄ and monoclinic Mg₂NiH₄ has been performed. It is found that the band structure of cubic Mg ₂NiH₃ is similar to that of crystalline Si (c-Si), whereas the band gap of monoclinic Mg₂NiH₄ is similar to that of the hydrogenated amorphous Si (a-Si:H). It is shown that cubic Mg ₂NiH₄ possesses the features of semiconductors such as wide fundamental band gap, capability for n- and/or p-type electrical conductivity, and small carrier effective masses. It is concluded that Mg ₂NiH₄ can be considered as a candidate, which is capable to replace c-Si and a-Si:H. It might be useful for the processing of electronic devices such as, e.g., solar cells at low temperatures. Advantages of using hydrides in semiconductor electronics are discussed.