Multilayers as Microlabs for Point Defects: Effect of Strain on Diffusion in Semiconductors

We describe how a systematic variation of experimental parameters can turn multilayers into microscopic laboratories for point defects. The effects of composition, doping, and strain on point defect diffusion and interdiffusion can thus be separated. This approach also allows one to determine the nature and the charge state of the mediating defect. More specifically, our results show interdiffusion in the model system InAlAs is mediated by a double-acceptor, vacancylike defect, with an activation energy of 4.0 eV in ${\mathrm{In}}_{0.52}$ ${\mathrm{Al}}_{0.48}$As. This activation energy changes by 51 meV per% strain.