X-ray scattering investigation of semiconductor nanocrystals in amorphous matrix

Semiconductor nanocrystals in amorphous matrix are intensively studied nowadays because of their prospective applications in photonics and as photovoltaic elements. For these applications the homogeneity of sizes and chemical composition of the nanocrystals is an important issue. We have investigated the structure and processes of self-ordering of Ge nanocrystals in amorphous matrices (silica or alumina) deposited by dual magnetron sputtering. For the structure studies we used several x-ray scattering methods (small-angle scattering, standard and grazing-incidence x-ray diffraction) as well as direct methods such as TEM and AFM. The electronic and optical properties have been studied by IR Raman spectroscopy, IR absorption and DLTS method.
In order to improve the degree of ordering of the nanocrystals during the growth and during subsequent annealing steps we investigated different scenarios including post-growth irradiation by light ions and deposition on pre-patterned substrates. These approaches yield nanocrystal ensembles with enhanced self-ordering and improved homogeneity.

Persona di contatto:Cinzia Giannini  

Sito web:http://www.ic.cnr.it

Telefono:080 592 9167/9154/9151

Relatore:Prof. Václav Holý della Charles University di Praga