Photoluminescence and photoreflectance study of annealing effects on GaAs0.909Sb0.07N0.021 layer grown by gas-source molecular beam epitaxy

Thermal annealing effects of a Ga As0.909 Sb0.07 N0.021 film grown on GaAs substrate via gas-source molecular beam epitaxy have been characterized by photoluminescence (PL) and photoreflectance (PR) techniques. PL measurements show the evolution of luminescence feature with the thermal annealing treatment. The conduction to heavy-hole (HH) band and conduction to light-hole (LH) band transitions originated from the strained induced valence band splitting in Ga As0.909 Sb0.07 N 0.021 layer have been observed by the PR measurements. The near band edge transition energies are slightly blueshifted, and the splitting of HH and LH bands is reduced with rising annealing temperature. The temperature dependences of near band edge transition energies are analyzed using Varshni and Bose-Einstein expressions in the temperature range from 15 to 300 K. The parameters that describe the temperature variations of the near band edge transition energies are evaluated and discussed. © 2008 American Institute of Physics.