Temperature dependence of photoluminescence in InAsP/InP strained multiple quantum wells

The photoluminescence spectra of InAsP/InP strained multiple quantum wells have been experimentally determined in the temperature range 7–300 K. In order to understand the temperature behavior of the photoluminescence, a theoretical calculation is presented that takes into account the temperature-induced variations in band gap, carrier effective mass, biaxial strain, and exciton binding energy. The results show that the energy of the transition E1H between the n=1 electron subband and the n=1 heavy-hole subband changes as a function of temperature, and depends mainly on the evolution of the strained band gap of the InAsP layers. This is because in the temperature range 7–300 K the variations of the electron subband energy and the exciton binding energy are much less than those of the strained band gap, while the variation of the heavy-hole subband energy can be neglected. These results also explain why, for a lattice-matched quantum well, the variation of exciton peak energies with temperature follows that of the forbidden energy gap of the bulk material in the well.