Polaronic excitons in ${\mathrm{Zn}}_x{\mathrm{Cd}}_{1-x}\mathrm{S}\mathrm{e}/\mathrm{Z}\mathrm{n}\mathrm{S}\mathrm{e}$ quantum wells

Magneto-optical absorption of quantum wells exhibits distinct excitonic resonances and allows the determination of exciton binding energies and diamagnetic shifts. Here, we report a magneto-absorption study on ${\mathrm{Zn}}_{0.69}{\mathrm{Cd}}_{0.31}\mathrm{S}\mathrm{e}/\mathrm{Z}\mathrm{n}\mathrm{S}\mathrm{e}$ multiple quantum wells 4 and 5 nm thick yielding $1S$ exciton binding-energy values. These results are compared to calculations based on two theoretical models that include the exciton-phonon interaction potential or the screened Coulomb potential. This analysis allows us to discriminate between the two models and highlights for the first time the impact of polaronic coupling on the optical behavior of these polar heterostructures.