Saturday, May 28, 2016
Abstract-Terahertz emission from SiC natural superlattices in strong electrical field
Results are reported from a study of the terahertz from 8H-, 6H-, and 4H-SiC natural under the action of an electrical field applied along the natural axis. It is shown that the single, relatively narrow emission lines (L1-lines) dominate in the at moderate bias voltages and follow the increase of the width of the first mini-band of the in accordance with the criterion for Bloch oscillations. At bias voltages well above the Bloch oscillation threshold, the structure of the undergoes considerable changes, which occur due to the appearance of a new intense, broader emission line (L2-line) with a maximum at about 12–13 meV. Tentatively, this latter emission is attributed to optical transitions between Wannier-Stark ladders formed from degenerate states in a side minimum of the SiC under strong conditions.