  Wide quantum dots were fabricated from multiple quantum well structures based
on Zn_{1-x}Mn_xTe/ZnTe (x = 0.076) dilute magnetic semiconductors and were
investigated via photoluminescence (PL) in a magnetic field. Calculations
taking into account the strain in the two types of structure enabled the PL
transitions to be identified and show that the dominant emission in the MQWs is
from heavy-hole (hh) excitons whereas in the quantum dots, the removal of the
strain in the barrier layers generates a large biaxial tensile strain in the
quantum wells which shifts the light-hole (lh) exciton to lower energy than the
hh exciton. The lh exciton sigma^+ transition is virtually independent of
magnetic field whilst the hh exciton is field-dependent. Thus, at fields of 1
to 2 Tesla, the hh exciton sigma^+ transition again becomes the lowest energy
transition of the quantum dots. These observations are described by a model
with a chemical valence band offset of 30% for Zn_{1-x}Mn_xTe/ZnTe.
