This paper describes molecular beam epitaxial growth and photoluminescence (PL) properties of PbTe quantum wells (QWs) and quantum dots (QDs) in CdTe matrix. Cross-sectional observation by atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM) revealed that the PbTe epitaxy mode on CdTe(1 0 0) turned from a conventional two-dimensional (2D) QW-growth at 220 degrees C to a highly isotropic QD-growth at 280 degrees C by minimizing the interface energy between rocksalt PbTe and zincblende CdTe. Although both the QWs and QDs can emit mid-infrared PL, the emission from QDs was much stronger and observed even at higher temperatures over 400 K. Below 120 K, however, this intense emission from QDs became low due to the band-alignment change from type-I to type-II by the thermal mismatch between PbTe and CdTe. (c) 2006 Elsevier B.V. All rights reserved.