Migration processes of the As interstitial in GaAs

Abstract

Thermal migration processes of the As interstitial in GaAs were investigated using density-functional theory and the local-density approximation for exchange and correlation. The lowest-energy processes were found to involve the À1, 0, and þ1 charge states, and to produce migration along h110i-type directions. In the À1 and 0 charge states, migration proceeds via hops between split-interstitial stable configurations at bulk As sites through bridging saddle-point configurations in which the interstitial atom is equidistant from two adjacent bulk As sites. In the þ1 charge state, the roles of these two configurations are approximately reversed and migration proceeds via hops between bridging stable configurations through higher-energy split-interstitial stable configurations bounded by a pair of distorted split-interstitial saddle-point configurations. The predicted activation energies for migration in the 0 and þ1 charge states agree well with measurements in semi-insulating and p-type material, respectively. Also consistent with experiments, the approximate reversal of the stable and saddle-point configurations between the 0 and þ1 charge states is predicted to enable carrier-induced migration with a residual activation energy of 0.05 eV. Published by AIP Publishing.

Anomalous Behavior of the Elastic and Optical Properties in Bi1.5Sb0.5Te1.8Se1.2 Topological Insulator Induced by Point Defects

“…The result of applying Equation to our data is presented in Figure . The obtained activation energy value V 0 = 78.7 meV is higher than that for point defects in semiconductors, but comparable to the one determined by changing the configuration of short and long Ge‐Te bonds in GeTe …”

“…Next, we discuss the anomalous behavior of the elastic properties of BSTS. The peak on the temperature dependence of the ultrasound attenuation and the step‐like anomaly of the elastic modulus are the typical features that manifest themselves in the ultrasound experiment and characterize the anelastic relaxation in solids containing point defects . The anelastic relaxation can be induced only by the defect whose symmetry system is lower than the crystal symmetry .…”

Ab Initio Studies of the Diffusion of Intrinsic Defects and Silicon Dopants in Bulk InAs

“…The simulations were performed with norm-conserving Perdew–Zunger pseudopotentials within the Local Density Approximation (LDA) level of theory. An LDA level of theory has been shown to be an appropriate choice for defect formation and migration energy calculations for III–V systems of this type. , This has also been confirmed by some of our calculations (not reported here) that show negligible improvement when using GGA rather than LDA for Nudged Elastic Band (NEB) calculations in the closely related system of CuAu-I In 0.5 Ga 0.5 As .…”

“…One such configuration is shown in Figure . The presence of split-interstitial As configurations have recently been reported in In 0.5 Ga 0.5 As by Reveil et al and in GaAs by Wright et al On the other hand, Si strongly prefers to occupy hexagonal sites, although tetrahedral configurations are also relatively feasible. An example hexagonal configuration for Si is shown in Figure .…”

Adsorption and interface reaction in direct active bonding of GaAs to GaAs using Sn–Ag–Ti solder filler

“…However, in our TEM test results there is no As-Ti phase found. Maybe because arsenic is easy to volatilize that will lead to volatilization in the process of TEM sample preparation [23][24][25]. As the triangle area is too small and the substance formed at the interface is quite brittle, it is quite hard to make a satisfactory sample.…”