Superlattices of a-SiO_x /nc-CdSe and thin composite films of SiO_x doped with CdSe nanocrystals have been investigated. The CdSe nanocrystals size in both kinds of samples was determined by x-ray diffraction and HREM measurements. A significant difference has been found in the size values determined by both methods, which has been ascribed to appreciable nanocrystal lattice deformations. Subband absorption, room-temperature photoluminescence and thermally stimulated currents have been measured. It has been observed that in the superlattices the absorption in the tail region increases as sublayer thickness decreases. A new photoluminescence band has also appeared in the superlattices having thinnest (2.5 nm) CdSe sublayers. Two new maximums at about 220 K and 240 K, not existing in the CdSe single layers studied, have been found in thermally stimulated current spectra of the composite films. Both maximums are less expressed in the superlattices. The described results have been connected with a size-induced increase in the concentration of interface defect states in CdSe nanocrystals. It has been estimated that these defects are disposed at about 0.35 eV above the highest occupied molecular orbit in CdSe.

Oxide-based materials have a variety of applications in chemical sensing and photocatalysis, thin-film transistors, complex-oxide field-effect transistors, nonvolatile memories, resistive switching, energy conversion, topological oxide electronics, and many others. The radiation resistance of these materials in such devices plays an important role in device operation in radiation environment, and this attracts much attention in the research area. In spite of damage in a number of cases high-energy particles may have a beneficial effect on the target. In this mini-review article examples of both creation of defects and beneficial changes in the structure and properties of homogeneous and nanostructured oxides caused by high-energy electron and neutron irradiation are given by considering some recently published results. First, the attention is turned to ionizing and displacement effects of electron and neutron irradiation in homogeneous bulk and thin-film oxides reported in the literature. Then, the effect of electron and neutron irradiation on nanostructured oxides and semiconductor nanoparticles embedded in an oxide matrix is regarded. Considerable attention is paid to silicon oxide layers since they are widely used in microelectronic products, which are among the most manufactured devices in human history. Processes of irradiation-induced lattice rearrangement, compositional changes, growth of nanoparticles and their size reduction, creation of point defects and their complexes, electron-hole generation, and charge trapping are discussed.