On the difference in the binding energy of 1s and 2s excitons in CdTe/(Cd,Mg)Te

Photoluminescence and reflection spectra in CdTe/(Cd,Mg)Te quantum wells with a width of 60 $\mathring{\mathrm{A}}$ with varying degrees of doping have been experimentally studied. It was found that, in accordance with previous calculations, an exciton state is observed approximately 17 MeV above the basic level of heavy exciton (1s 1$e$1$hh$). By all indications, this condition should be associated with the exciton 2s 1$e$1$hh$. In addition, another signal is observed higher in energy, which most likely belongs to the exciton with a light hole 1s 1$e$1$lh$.