Intersubband energies in Al1−yInyN/Ga1−xInxN heterostructures with lattice constant close to aGaN

We have studied the conduction band profile and the intersubband transition energy, E12, of Al1−yInyN/Ga1−xInxN quantum well structures. We have considered how material parameters such as non-parabolicity and the uncertainty in the bowing parameter affect E12 and the corresponding wavelength, λ12. The calculations include strain and cover the transition range from telecommunication wavelengths (1.55 μm) to the mid-infrared (∼ 10 μm).Our results show that the transition energies of strain-free Al1−yInyN/Ga1−xInxN quantum well structures, which are lattice-matched to GaN (y = 17.7%, x = 0), resulted in wavelengths above ∼2 μm. To reach shorter wavelengths, we explored structures with other indium concentrations but maintaining a small mismatch to GaN. For ∼1% lattice mismatch the wavelength λ12 could be reduced to less than 1.55 μm. The results serve as a starting point for designing and epitaxial growth of photonic intersubband structures.

► Al1−yInyN/GaN heterostructures lattice matched to GaN.
► Al1−yInyN/Ga1−xInxN heterostructures strain balanced to GaN.
► Al1−yInyN/Ga1−xInxN heterostructures with QW lattice matched to GaN.
► Al1−yInyN/Ga1−xInxN heterostructures with barrier lattice matched to GaN.