ABINITIO CALCULATIONS ON THE PASSIVATION OF SHALLOW IMPURITIES IN GAAS

The results of the first ab initio calculations performed on the complexes formed between hydrogen and both donor and acceptor atoms in gallium arsenide are reported. The equilibrium geometries and electronic properties are presented. For the first time a parameter-free determination of the vibrational properties of the entire defect complex has been performed, allowing a more complete comparison with infrared-absorption experiments. Local structural distortions far larger than previously expected are proposed to account for the absence of certain absorption lines. © 1990 The American Physical Society.