Ionization levels (solid lines) used by Gebauer et al. (Ref. 2); they are taken to have a negative temperature dependence and vary like the experimental band gap. The position of the extrinsic Fermi level is also shown (dash line).
Ionization levels (solid lines) as obtained by Bracht et al. (Ref. 1) from a fit of the experimental data in the temperature range of and are assumed to remain constant. The position of the extrinsic Fermi level is also shown (dash line).
Entropy and enthalpy (inset) differences obtained after the progressive ionization of . While shows little temperature dependence, the nonvanishing entropy difference between charge states lead to a linearly increasing entropic term in the Gibbs free energy.
Stability domains of in GaAs as function of temperature, indicated by the charge state. Each region denotes the temperature and the doping range where a charge state dominates self-diffusion. The dashed lines show the typical position of the chemical potential as function of temperature for , , and intrinsic conditions. At temperatures above the competition between different charges becomes significant.
Experimental measurement (filled circle) and fit (dashed line) for temperature dependence of the vacancy concentration, as reported by Gebauer et al. (Ref. 2). Our calculation including and contributions (solid line) is shown together as well as separately (dotted line).
Gallium self-diffusion constant vs inverse temperature for (a) type, (b) intrinsic, and (c) type. Theoretical results for (dashed lines) show the contribution of each charge state. The transition temperature lies at the crossing of the curves. The total (solid) is in good agreement with the measured interdiffusion data (square) and fit by Bracht et al. (Ref. 1) (circle).
Calculated formation entropies and formation enthalpies for in GaAs are compared to earlier calculation and experimental fits.
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