A systematic first-principles total energy calculation is performed to investigate the structural and electronic properties of $[{\mathrm{P}}_{\mathrm{In}}{]}^{\mathrm{}\left(n\right)\mathrm{}}$ antisite clusters in InP, with n up to four. Isolated ${\mathrm{P}}_{\mathrm{In}}$ antisites generate a defect level in the gap region with a relatively large energy dispersion in our 128 atoms supercell. For clusters formation with 2, 3, and 4 antisites, the corresponding energy dispersion of the defect levels decrease and a confinement tendency of the carrier density is observed, mainly for clusters in the two-dimensional topology. The resulting character of the defect levels in the gap and their corresponding energy dispersions are associated with the origin of the n-type conductivity in intrinsic InP growth at low temperature. Our calculation indicates that the clustering of ${\mathrm{P}}_{\mathrm{In}}$ antisites is an energetically favorable process. A hypothetical planar doping system, formed by high concentration of antisites, is proposed as a possible structure.

• Received 29 June 1999

DOI:https://doi.org/10.1103/PhysRevB.60.16475