A new insight into the way semiconductors work could pave the way for the next generation of electronic devices.
Atoms move through the crystal lattice of a solid by a process called diffusion.
In a semiconductor structure, a solid is doped with 'foreign' atoms that carry charge. Since these charge carriers move by a similar diffusion process, a better understanding of the phenomenon could enable scientists to develop more efficient semiconductors. SIMS allows diffusion to be monitored for a longer period than was possible with earlier methods, which were limited by the half-lives of radioactive 'tracer' atoms they used. The discrepancy occurs near the melting point of GaSb, and cannot easily be explained by conventional theories of diffusion. Bracht's team proposes a new mechanism for the effect, in which reactions between defects on the Ga and Sb sublattices remove the defects that are necessary for the migration of the Sb atoms.