„Atomic scale study of emerging UV-light LEDs by advanced transmission electron microscopy”
(acronym: UV-LED)

Project supported by the National Science Centre, Poland under the „POLONEZ 1” programme

Total cost: 550 416,00 PLN
Centre Contribution: 550 416,00 PLN
Duration: 01/01/2017-31/12/2018

Principal Investigator: Sandeep M. Gorantla, PhD

The main goal of this project is to conduct basic experimental research at atomic scale; on emerging pn-junction AlxGa1-xN based ultra-violet light (UV-light) light emitting diodes (LEDs) by advanced atomic resolution Transmission Electron Microscopy (TEM). Both the structural and electronic properties of these LEDs will be investigated in this project by TEM. This will allow gaining more fundamental understanding of these emerging LEDs. AlxGa1-xN UV-LEDs show the promise as a potential candidate for next generation UV-C (wavelength range 100 – 290 nm) light LED source for water purification applications. However, currently, the practically achievable external quantum efficiency (EQE) of AlxGa1-xN UV-LEDs is in the range 1-2 %. The factors (e.g. defects, Mg dopant atom clustering, lattice strain) responsible for limiting their efficiency are known but not yet fully understood. Another crucial objective of this project is to focus and study two fundamental scientific problems associated with AlxGa1-xN UV-LEDs. A major factor limiting the performance of wide bandgap p-n-junctions is the drift of Mg ions, especially in highly polar wurtzite material such as AlxGa1-xN. Other problem is the lattice strain in the different thin film layers of a UV LED device.