What is it about?
In polar (c-plane) InGaN/GaN quantum wells the In atoms are distributed at random, at least for In concentrations less than 25%. We show that for m-plane quantum wells the In distribution is increasingly non-random as the In concentration increases, so that In-rich clusters are formed
Featured Image
Why is it important?
Originally it was thought that the reason InGaN/GaN LEDs were so bright when the dislocation density was so high was because the InGaN quantum wells contained gross In-rich clusters which localised the carriers (electrons and holes), keeping them from diffusing to the dislocations. It was then shown by Smeeton et al that the In-rich clusters observed by TEM were due to electron beam damage. Further work by Galtrey et al showed that InGaN was a random alloy. This paper surprisingly shows that in m-plane InGaN, In-rich clusters are increasingly formed as the In content is increased. This is important for the light-emitting mechanism in this orientation.
Perspectives
The publication shows the power of atom probe tomography in determining the atomic structure of semiconductor quantum wells
Colin Humphreys
Queen Mary University of London
Read the Original
This page is a summary of: Insight into the impact of atomic- and nano-scale indium distributions on the optical properties of InGaN/GaN quantum well structures grown on m-plane freestanding GaN substrates, Journal of Applied Physics, June 2019, American Institute of Physics,
DOI: 10.1063/1.5097411.
You can read the full text:
Contributors
The following have contributed to this page
