Iyevlyev D. Photon emission from metal clusters

The thesis is devoted to study of photon emission from metal clusters under different excitation. It was shown that previously discovered effect of chemiluminescence arising from agglomeration of small Ag clusters in noble-gas matrices could be reproduced by condensation of Ag atoms onto freely moving noble-gas cluster. This effect is caused by the gain in binding energy by the clustering process. It was shown that the peak positions in the spectra recorded with the agglomeration of silver clusters in noble-gas droplet are shifted slightly to lower wavelengths comparing to the spectra recorded previously in bulk noble-gas matrices. This shift inreases with decreasing of size of noble gas cluster (nanomatrix). This re-sult reflects the reduction of the effect of neighboring Ar atoms on the energetics of the excited Ag clus-ters. Also the photon emission spectra of nanoclusters (island films) of different metals (Ag, Cu, Pd) were studied under passage of conduction current as well as under low-energy ele ctron bombardment. For the first time such research were performed in the wide range (200-1050 nm) with high resolution and sensi-tivity. It was shown that new peaks can arise in high-energy section of the spectra with decreasing of the particles size. The high-energy section of the spectra develops as the input power increases. It's shown that expressed in volts energy of photons emitted from the island film under the passage of electrical current through it can exceed the voltage applied to this film. The comparison of the spectra measured at two different excitation modes (by the passage of electrical current and by low-energy electron bombardment) shows that in both cases light emission is caused by similar reasons. It's shown that the light emission with line spectrum from atoms and molecules of the residual gases adsorbed on the clusters is intensively excited when pressure of the residual gases exceeds mbar. These phenomena can be reasonably ex-plained in the framework of the model of hot electrons. M ultyply-twined silver particles of new shape have been found. They have strongly prolate shape. The relation of the length of such particle to the lateral size can reach 10:1. Such particle is strongly trun-cated by planes of the (100) type decahedron with the 5-fold symmetry axis which is parallel to a sub-strate.