In this communication we show that the cancelation of excitonic effect
s by photo-injected carriers can be easily produced in ZnSe-ZnTe super
lattices. This combination is interesting: it has a type 11 band align
ment in real space. Strong confinements of electrons and holes by larg
e bands offsets lead to important values of Rydberg energies, thus, im
portant energy-shifts of some 20 meV are measured when exciton screeni
ng is produced in such superlattices.