The irreversible formation of a network of linear defects was observed in images which exhibited recombination luminescence from injection diodes in hexagonal carbide samples. The defects were related to dislocations that had initially formed as a result of thermal stresses near to the tip of the contact probe and which then propagated through the diode area. The dislocation network appeared, in electroluminescence images, as bright-line defects and contrasted with the well-known dark-line defects that were due to the degradation of GaAs-based light-emitting devices. Higher forward currents were found to promote dislocation growth.

A.O.Konstantinov, H.Bleichner: Applied Physics Letters, 1997, 71[25], 3700-2