  We explore CdTe fractional monolayer quantum dots (QDs) in a ZnCdSe host
matrix for potential application in an intermediate band solar cell device.
Careful consideration has been taken during the initiation of the growth
process of QDs by migration enhanced epitaxy, in order to avoid the formation
of undesirable interfacial layers that can form due to the lack of common anion
between the two materials. A superlattice structure of 100 periods of
alternating QD and spacer layers is analyzed by high resolution X-ray
diffraction (XRD) and photoluminescent (PL) spectroscopy. Simple arguments are
used following continuum elastic theory to deduce the size of the dots and the
strain within the superlattice from XRD data. This is further verified using PL
and used in the energy calculations that yield the values of the intermediate
band energy. The results suggest that the optimized materials are highly
suitable for these high efficiency solar cells.
