Calculation Of Positron Characteristics In Silicon Carbide

Positron affinity calculations performed by a first-principles approach based on density functional theory reveal, contrary to many other semiconductors, that free positrons and positronium atoms can escape from SiC. It is found that the treatment of the electronpositron interaction plays a crucial role when calculating the annihilation characteristics. These characteristics originating from both valence and core electrons, combined with the corresponding measurements, yield a very useful tool for surface studies and point defect identification in the bulk. Calculations will be compared with available experimental data.