Interband transitions in molecular-beam-epitaxial AlxGa1−xAs/GaAs

Abstract

Interband transition energies for Al_xGa_1−xAs layers grown by molecular‐beam epitaxy (MBE) techniques have been determined using the electrolyte electroreflectance (EER) technique. The observed data fit quadratic relations for E₀, E₀+Δ₀, E₁ and E₁+Δ₁ to describe variations of energy with composition. Although the x values were not accurately known, the internal consistency of the data is excellent. Given a single bowing parameter we show that accurate values of x can be determined. The EER technique can provide x values with an accuracy better than 0.02 and information on changes in x as small as 0.002. It is thus ideally suited for studying MBE materials.