Photo-induced interband absorption in group-III nitride quantum wells

We solve self-consistently Schrödinger and Poisson equations for GaN/AlGaN quantum wells, to analyze the change of optical spectra under high optical excitation. Electric fields of View the MathML source or higher are present along the growth axis of such quantum wells. The induced separation of electron and hole wave functions reduces the oscillator strength of the ground-state optical transition, whereas those involving excited states give a much larger absorption. In presence of large electron–hole pair densities, we show that the optical density can be either reduced or enhanced, depending on the spectral region involved.