Luminescence and structure of introduced dislocations in GaN

What is it about?

Defects can be efficient sources of luminescence and can be used for developing new types of LEDs. This article is focused on dislocations in GaN, which were introduced after growth by mechanical deformation on crystal surface. They exhibit strong luminescence with its characteristic energy connected to their structure. In particular, this article describes luminescence from perfect and dissociated dislocations together with extended dislocation nodes (nodes are formed at dislocations intersections).

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Photo by Guillaume TECHER on Unsplash

Photo by Guillaume TECHER on Unsplash

Why is it important?

We have established characteristic energies (in relation to the near-band-edge emission) of luminescence of introduced defects (perfect and dissociated dislocations, extended dislocation nodes), which were studied separately previously. We also proved their coexistence in a structural study. These facts allowed to argue that type of forming defects is not a property of a material and it is connected to features of mechanical deformation. Also, based on our findings we proposed a tentative model for electrostatic interaction between oppositely charged N and Ga partials of dissociated dislocations.