Temperature dependence of the energy and broadening parameter of the fundamental band gap of GaSb and Ga1-xInxAsySb1-y/GaSb (0.07≤x≤0.22, 0.05≤y≤0.19) quaternary alloys using infrared photoreflectance

We have measured the temperature dependence of the energy [E-0(T)] and broadening parameter [Gamma (0)(T)] of the fundamental gap for GaSb and four samples of Ga1-xInxAsySb1-y (lattice matched to GaSb) using infrared photoreflectance. The parameters that describe the temperature variation of the energy (including thermal-expansion effects) were evaluated using both the semiempirical Vashni relation as well as an equation that incorporates the Bose-Einstein occupation factor. The behavior of Gamma (0)(T) was described by a Bose-Einstein-type equation.