Method to probe the electrical activity of dislocations in non-intentionally doped n-GaN

Here is presented a method to probe the electrical activity of dislocations in non-intentionally doped n-GaN epitaxial layers based on the study of their sub-band gap photoconductivity, monitoring their electron concentration and mobility. Non-intentionally doped n-GaN layers bearing charged and thus highly dispersive and recombining dislocations when illuminated with sub-band gap photons show a strong increase on their conductivity, due to an equivalent increase on the electron mobility while the electron concentration remains unchanged. On the other side, non-intentionally doped n-GaN layers bearing electrically inactive dislocations display almost no photoconduction, as both; carrier concentration and their mobility remain unchanged under the same illumination conditions. The method, simultaneously assess the electrical activity of dislocations and the material quality, and can be applied to any other semiconducting material bearing high dislocations densities.

► This is the first method proposed to probe the electrical activity of dislocations.
► Based on Hall and resistivity measurements under sub-bad gap illumination. High sensitivity to the charge contained at the dislocations.
► Is non destructive.
► And can be applied at some point in the processing of samples and devices.