The fine structure of electron irradiation induced EL2-like defects in n

Defects induced by electron irradiation in n-GaAs have been studied using deep level transient spectroscopy (DLTS) and Laplace DLTS (L-DLTS). The E0.83 (EL2) is the only defect observed prior to irradiation. Ru/n-GaAs Schottky diodes were irradiated with high energy electrons from a Sr-90 radionuclide up to a fluence of 2.45 1013 cm 2. The prominent electron irradiation induced defects, E0.04, E0.14, E0.38, and E0.63, were observed together with the metastable E0.17. Using L-DLTS, we observed the fine structure of a broad base EL2-like defect peak. This was found to be made up of the E0.75, E0.83, and E0.85 defects. Our study reveals that high energy electron irradiation increases the concentration of the E0.83 defect and introduces a family of defects with electronic properties similar to those of the EL2.The authors gratefully acknowledge the financial support of the South African National Research Foundation (NRF) and the University of Pretoria.The South African National Research Foundation (NRF) and the University of Pretoria.http://scitation.aip.org/content/aip/journal/japam2016Physic

Defects induced by solid state reactions at the tungsten-silicon carbide interface

Defects introduced by the solid state reactions between tungsten and silicon carbide have been studied using deep level transient spectroscopy (DLTS) and Laplace DLTS. W/4H-SiC Schottky barrier diodes were isochronally annealed in the 100–1100 C temperature range. Phase composition transitions and the associated evolution in the surface morphology were investigated using x-ray diffraction (XRD) and scanning electron microscopy (SEM). After annealing at 1100 C, the E0.08, E0.15, E0.23, E0.34, E0.35, E0.61, E0.67, and E0.82 defects were observed. Our study reveals that products of thermal reactions at the interface between tungsten and n-4H-SiC may migrate into the semiconductor, resulting in electrically active defect states in the bandgap.The South African National Research Foundation (NRF) and the University of Pretoria.http://aip.scitation.org/journal/jap2019-01-18am2018Physic

Optically Addressable Magnesium-Vacancy Color Centers in Diamond

We report on a systematic optical and structural investigation of the MgV color center in diamond. The results show unique tunable properties of the center making it appealing for its utilization in quantum information processing