Quantum-chemical study of structural and electronic properties of silicon nanoclusters doped by phosphorus

Phosphorus doping effects on structural and electronic properties of diamond-like nanoclusters Si₂₉H₃₆, Si₅₉H₆₀, Si₇₁H₆₀ with sizes of 0.88 nm, 1.26 nm and 1.41 nm have been investigated by ab initio method ORCA. The structural deformation of clusters initiated by presence of single phosphorus atom depends on cluster size and its location. Calculated formation energies of pure and doped clusters show that the more stable state of phosphorus atom is the subsurface positions. Energy gaps between the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals considerable greater than that for bulk silicon and depend on nanocluster size. It is demonstrated that P-doping introduces energy levels in the cluster energy gap, and spin split occurs for all configuration (authors)