Various designs of AlGaN/GaN structures displaying intersubband absorption in the THz spectral range are reported upon. Firstly, samples with 3‐layer quantum wells (step‐quantum‐wells) displaying far‐infrared intersubband absorption are presented. Theoretical analysis of the reproducibility issues associated to this architecture is done, and a more robust design based on 4‐layer quantum wells is proposed. Such a structure has been fabricated by plasma‐assisted molecular‐beam epitaxy using two Al effusion cells to produce three AlGaN concentrations, without growth interruptions. Samples have been structurally validated by transmission electron microscopy and X‐ray diffraction. Fourier transform infrared spectroscopy measurements show far‐infrared absorption of TM‐polarized light, which gets broader and deeper for increasing doping levels.

III‐nitride nanostructures have recently emerged as promising materials for new intersubband (ISB) technologies in a wide variety of applications. These ISB technologies rely on infrared optical transitions occurring between quantum‐confined electronic states in the conduction band of GaN/Al(Ga)N nanostructures, namely quantum wells or quantum dots. When producing optoelectronic devices at the nanoscale, the errors induced from growth should not make or break a design. In their research presented on pp. http://doi.wiley.com/10.1002/pssa.201300431, Monroy et al. theorize and demonstrate designs for THz absorption with robustness to these growth‐induced errors.