Optical Absorption in Polarized Ga1 xInxN/GaN Quantum Wells

The density of states optical absorption edge in polarized Ga1 xInxN/GaN quantum wells (x 0:14) is studied through photoluminescence excitation spectroscopy and effective mass theory. Within the vicinity of the main absorption edge in the range of 3.0–3.3 eV several extrema are resolved. On the basis of experimental polarization field values and established parameters a model of the electronic band structure in the quantum wells is derived. Both predicted interband transition energies as well as relative matrix elements provide a good description of the observations and a level assignment. We thus identify a dominance of e1lh1 and e1hh1 transitions with increasing competition by e1hh2 for higher x. Due to the strong polarization effects, the latter is an allowed transition and paired with the high lying ionization threshold to the valence band. These results provide a quantitative basis for the further identification of the electronic band structure in polarized heterostructures. [DOI: 10.1143/JJAP.41.11]