Energy band/lattice mismatch engineering in quaternary AlInGaN/GaN heterostructure

We discuss structural, optical and electrical properties of AlxInyGai-x-yN/ GaN heterostructures grown on sapphire and GH-SIC substrates. The incorpora tion of In reduces the lattice mismatch in a much stronger way than the ene rgy gap discontinuity. An In to Al ratio close to 1:5 should result in near ly strain-free heterostructures. The incorporation of In and resulting chan ges in the built-in strain in AlInGaN/GaN heterostructures strongly affect the transport properties of the two-dimensional (2D) electron gas at the he terointerface. Using the incorporation of In in order to increase the Al mo lar fraction preserving the same value of strain should allow us to greatly enhance the sheet carrier density at the AlGaInN/GaN heterointerface. Furt her work on improving In incorporation techniques is needed in order to mee t these expectations.