Subband transitions in AlxGa1-xN/GaN/AlxGa1-xN and AlxGa1-xN/InN/AlGa1-xN single quantum wells

We have calculated the spectral regime of subband transitions in AlxGa1-xN/GaN and AlxGa1-xN/InN single quantum wells. We used a simplified model to account for the internal electric fields, which modify the shape of the quantum well. Some of the parameters for these materials have not yet been firmly established. Therefore, we carried out the analysis for the extremes of the reported values of conduction band discontinuities and band gaps (in the case of InN). This analysis shows that the spectral regime of interband transitions for 1-4 nm thick wells has wavelengths above 0.5 mu m for AlGaN/lnN and above 0.8 mu m for AlGaN/GaN and both heterostructures cover several pm wavelengths. The spectral variation with alloy composition is less pronounced in the AlxGa1-xN/InN single quantum wells due to the higher electric field present across the InN quantum well as compared to GaN. The results of these calculations are in good agreement with more rigorous theoretical approaches and available experimental values for AlxGa1-xN/GaN. (C) 2005 Elsevier Ltd. All rights reserved.