| In the Project, we will explain the role of point defects (mainly Ga vacancies and hydrogen impurity) in decomposition of InGaN quantum wells. This decomposition occurs during growth of p-type GaN above these wells in LEDs and laser diodes (LDs) emitting in blue/green spectral range, and is one of the main reasons why the efficiencies of green emitters have low efficiencies ("green gap"). In our recent research, we got for the first time indications that the InGaN decomposition is caused by strain-driven diffusion of point defects. To understand this phenomenon, we are planning to do a number of experiments changing growth parameters (doping, flows of reactants, pressure, temperature, etc) in epitaxial growth, as well as to do theoretical modelling of point defect and indium diffusion. The samples will be examined using a number of techniques in collaboration with other labs. As a result, we should find the way of avoiding the InGaN decomposition in LEDs and LDs. |
