Composition dependence of photoluminescence of AlxGa1−xAs grown by molecular beam epitaxy

Abstract
Low‐temperature (∼4 K) photoluminescence of lightly Si‐doped AlxGa1−xAs grown by molecular beam epitaxy has been studied. The defect‐related emissions, due to the defect exciton (d, X) and the defect complex (d), have been identified. The peak energies of these emissions, which are 1.505 eV (d, X) and 1.474 eV (d) for GaAs, have been determined as a function of the mole fraction x ( xx=0 to about 70 meV at x∼0.4. In addition, the ionization energies of carbon and silicon acceptors in AlxGa1−xAs have been determined as a function of x and compared with theoretical calculations.