Electronic structure of doped fourfold coordinated amorphous semiconductors. Midgap states in amorphous carbon

摘要

Midgap states have been studied in phosphorus-doped, tetrahedrally coordinated amorphous carbon by means of the Fragment Self-Consistent Field method (FSCF). It has been found that the midgap energy levels are primarily determined by the relative position of dopants. A simple linear correlation has been obtained between the highest occupied molecular orbital (HOMO) energy of the model clusters and the inverse distance of impurities.