Photoluminescence spectral features of mg-doped (Al)GaN epitaxial layers

Doping of p-GaN epitaxial layers (EL) and p-AlxGa1-xN solid solutions with magnesium impurity is complicated by the self-compensation effect associated with the appearance of donor states in the bandgap at a certain concentration of introduced acceptor atoms. Based on the spectra obtained by the photoluminescence method, it is possible to track the appearance of self-compensation in (Al)GaN:Mg EL and establish the optimal consumption of the introduced magnesium impurity, which allows obtaining a relatively high concentration of the majority charge carriers. Objective – Study of charge carrier concentration dependence in GaN:Mg and Al0.2Ga0.8N:Mg on Mg dopant flow rates, determination of optimal doping parameters, and investigation of photoluminescence spectral features in the obtained epitaxial structures. Results: The photoluminescence spectra of GaN:Mg and Al0.2Ga0.8N:Mg samples with varying dopant flow rates were measured. Analysis of these photoluminescence spectra enables determination of optimal growth conditions for p-type (Al)GaN epitaxial structures that avoid self-compensation effects detrimental to charge carrier concentration. Photoluminescence spectroscopy monitoring of self-compensation effects enables fabrication of high-quality p-(Al)GaN epitaxial structures suitable for optoelectronic device applications.