Optical and electrical properties of vanadium and erbium in 4H-SiC
Abstract
Local-density-functional calculations are carried out on vanadium and erbium centers in 4H-SiC. Particular attention is paid to their electrical and optical properties. We find that both V and Er lie at Si sites and can exist in three charge states with deep donor and acceptor levels. While isolated VSi possesses intra-d and ionization induced optical transitions around 0.94 and 2.9 eV respectively, the intense and temperature stable intra-f optical transitions due to Er are unlikely to be due to an isolated Er defect. It is suggested that both impurities can trap H and N forming complexes which may limit the electrical efficiency of V and act as Er related exciton traps.
- Publication:
-
Physical Review B
- Pub Date:
- May 2004
- DOI:
- 10.1103/PhysRevB.69.193202
- Bibcode:
- 2004PhRvB..69s3202P
- Keywords:
-
- 61.72.Bb;
- 61.72.Ji;
- 71.15.Mb;
- 71.55.-i;
- Theories and models of crystal defects;
- Point defects and defect clusters;
- Density functional theory local density approximation gradient and other corrections;
- Impurity and defect levels