Temperature dependence of quantized states in a GaAs/Al_0.23Ga_0.77As asymmetric triangular quantum well heterostructure

The piezoreflectance (PzR) measurements of a GaAs/Al_0.23Ga_0.77 As asymmetric triangular quantum well heterostructure as a function of temperature in the range of 20 to 300 K have been carried out. The structure was fabricated by molecular beam epitaxy using a digital alloy compositional grading method. A comparison of the PzR and photoreflectance spectra allows us to identify the features associated with the heavy- and light-hole valence bands unambiguously. The detailed study of the temperature variation of excitonic transition energies indicates that the main influence of temperature on quantized transitions is through the temperature dependence of the band gap of the constituent material in the well. The anomalous behavior of the temperature dependence of the linewidth of 11H excitonic feature is discussed.