OPTICAL-TRANSITIONS FROM BOUND TO EXTENDED STATES IN A SINGLE-QUANTUM-WELL WITH SYMMETRICAL BARRIERS

Formulas for the optical transition matrix element and absorption coefficient from a bound to exetended states in a single quantum well (SQW) are derived. The model is applied to a GaAlAs/GaAs single quantum well. The results show that the transition matrix element varies slowly over a wide energy range. Both narrow and broad absorption spectra are obtained. The peak absorption wavelength shifts to low energy as the well narrows. The results also show that the peak absorption coefficient is very sensitive to the well width when the well width approaches the critical value corresponding to the first excited state being located just at the top of the well. © 1993 Academic Press.