Design and Optimization of GaN/AlGaN Quantum Wells and Bragg Confined Structures for Short Wavelength (1.3μm<λ<2μm) Intersubband Absorption

A procedure is described for extracting the optimal structural parameters of AlGaN-based quantum wells and perturbed superlattices in order to achieve maximal intersubband absorption in the near infrared spectral range. Conventional quantum wells are chosen for their simplicity, while more complex structures relying on Bragg confinement are exploited to increase the transition energy between two quantized states. The well and the barrier widths and the Al content in both types of structures are varied in such a way that the peak absorption energy is kept constant, while searching for the largest value of dipole matrix element. The internal polarization fields and the nonparabolicity effects were taken into account. Finally, the optimal set of idealized structure parameters was used to perform fully self-consistent calculation for realistic, short-period structures.