Optical constants of AlxGa1-xN: Modeling over a wide spectral range

The optical constants of AlxGa1-xN have been modeled over a wide spectral r ange (up to 10 eV) and for all compositions 0 less than or equal to x less than or equal to 1. The employed model is the modified Adachi model for the dielectric function of hexagonal materials which utilizes an adjustable br oadening function instead of the conventional Lorentzian one. The broadenin g function can vary over a range of functions including Lorentzian and Gaus sian, enabling the model to dear with inhomogeneous broadening. Excellent a greement with the experimental data is obtained for all compositions. Obtai ned relative rms errors for all individual compositions are below 1.5% for the real part and below 2.5% for the imaginary part of the index of refract ion.