TEMPERATURE-DEPENDENCE OF QUANTIZED STATES IN AN INGAAS GAAS STRAINEDASYMMETRIC TRIANGULAR QUANTUM-WELL/

Photoreflectance (PR), contactless electroreflectance (CER) and piezor eflectance (PzR) measurements of an InGaAs/GaAs strained asymmetric tr iangular quantum well (ATQW) heterostructure as a function of temperat ure in the range of 20 to 300 K have been carried out. The structure w as fabricated by molecular beam epitaxy using the digital alloy compos itional grading method. A careful analysis of the PR, CER and PzR spec tra has led to the identification of various excitonic transitions, mn H(L), between the mth conduction band state to the nth heavy(light)-ho le band state. Comparison of the observed intersubband transitions wit h a theoretical calculation based on the envelope function model, incl uding the effects of strain, provide a self-consistent check of the AT QW composition profile. The detailed study of the temperature dependen ce of the excitonic transition energies indicates that the potential p rofile of the ATQW varies at different temperatures. The parameters th at describe the temperature dependence of E(mnH(L)) are evaluated. The anomalous behaviour of the temperature dependence of the linewidth of 11H, Gamma (11H)(T), is compared with recent results for GaAs/AlGaAs and InGaAs/GaAs symmetric rectangular quantum wells of comparable dime nsions.