Isovalent replacement method was used to obtain heterolayers of alpha-and beta-CdSe with high structure perfection, deposited on scintillator CdS < Te > and ZnSe < Te > crystals. Resulted monolith device has good properties for ionizing radiation detector applications. Our investigations revealed possibility to control device properties performing quantum-scale surface modification by corresponding annealing process. It was shown that modified surface material features significant increase of edge luminescence, transmission edge shift to long-wave region and wide spectral band corresponding to energies greater than CdSe bandgap. Observed peculiarities were explained in the frame of quantum-scale theory. (c) 2005 Elsevier B.V. All rights reserved.