Doping of saturated silicon clusters

The effect of the doping of silicon is studied with model clusters YSi4X12 and YSi34X36 for Y = Si, B, N, Al and P and pseudoatoms X which serve to saturate the structures. SINDO1 calculations are performed at the ROHF level. From the trend for the valence of the central atom Y for the cationic, neutral and anionic systems acceptors and donors can be identified. The MO diagrams show acceptor and donor levels. The results are in agreement with the notion that boron and aluminum are acceptors and nitrogen and phosphorus are donors. However, the donor property of nitrogen is not pronounced in the band structure.