Study of the band alignment in (Zn, Cd)Se/ZnSe quantum wells by means of photoluminescence excitation spectroscopy

We report on photoluminescence excitation spectroscopy performed on several (Zn, Cd)Se/ZnSe quantum wells at low temperature. Experimental results are compared with a calculation of the heavy- and light-hole excitonic transit ion energies. It is shown that the energy difference between the first heav y- and light-hole transitions E1H1 and E1L1 can be very sensitive to the va lence-band offset under some circumstances, making a determination of this parameter then possible. The strain-free relative valence-band offset is fo und q(v)(0) = 13% +/- 2%. The heavy-hole excitons are type-I excitons, wher eas the light-hole excitons are type-II excitons. (C) 2000 American Institu te of Physics. [S0021-8979(00)03804-4].