It was noted that mesoscopic point-like defects were a class of extended defects with surfaces of minimal curvature that ranged in size from multivacancy, antisite and impurity complexes to macroscopic inclusions or voids. The structural, electronic and optical properties of these defects evolved continuously from the quantum-mechanical limit to the classical limit. The mesoscopic defects shared some features in common with quantum dots, such as Coulomb-charging energies but, unlike quantum dots, their electronic properties were dominated by the covalent bond energies of the defect/semiconductor interface. The deep-level energies of spheroidal mesoscopic defects were calculated self-consistently in the unrestricted Hartree-Fock approximation, using an extension of the many-electron model of Haldane and Anderson. Calculations for GaAs revealed a high-multiplicity Coulomb ladder of discrete charge states which were distributed across the semiconductor band-gap and were centered on the charge neutrality level.

Mesoscopic point-like defects in semiconductors D.D.Nolte: Physical Review B, 1998, 58[12], 7994-8001