This paper describes self-organization of Pb0.7Sn0.3Te quantum dots (QDs) in a CdTe matrix and their photoluminescence (PL) properties by comparing with those of PbTe QDs in the same matrix. Owning to the large interface tension by the lattice-type mismatch of this heterosystem, postgrowth annealing brought a Pb0.7Sn0.3Te/CdTe quantum well into highly symmetric Pb0.7Sn0.3Te/CdTe QDs similar to the case of PbTe/CdTe heterosystem but with a little smaller QD size. Temperature dependent midinfrared PL spectra of these Pb0.7Sn0.3Te/CdTe and PbTe/CdTe QDs were explained by a theoretical calculation using the effective mass approximation and deformation potentials. (c) 2013 Elsevier B.V. All rights reserved.