Interstitial hydrogen and the dissociation of C-H defects in GaAs

• Local-density-functional calculations using a real-space cluster approach are used to model interstitial hydrogen in GaAs and the dissociation of the C-H and C-H- complexes. The equilibrium site is found to be on a Ga-As bond axis for H0 and H$+$/ and at a Ga anti-bonding site for H-. It is also shown that a H2 molecule is stable in interstitial space and has a lower energy than the two possible H2* defects and than widely separated single interstitial hydrogen atoms. The study of hydrogen in pure GaAs also yields the result that interstitial hydrogen is a negative-U defect. It is found that the energy barrier to the dissociation of the C-H complex is 1.8 eV, but that this is reduced to 0.9 eV for C-H-. Comparison is made with recent experimental results and implications for current containing devices are discussed.

Ämnesord

NATURVETENSKAP  -- Matematik -- Beräkningsmatematik (hsv//swe)

NATURAL SCIENCES  -- Mathematics -- Computational Mathematics (hsv//eng)

Nyckelord

Scientific Computing

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