engleski

Effect of nitrogen presence during the deposition on structural and optical properties of Ge quantum dot lattices in alumina matrix

Effect of nitrogen presence during magnetron sputtering deposition of Ge quantum dot lattices embedded in alumina matrix was studied. Three series of samples were deposited by varying substrate temperature, nitrogen flow rate and germanium content. The aim was to examine the effects of these parameters on structural and optical properties of the material and the self- assembled growth regime. It was shown that the presence of nitrogen affects the size of Ge QDs, their oxidation and optical properties. Furthermore, it was shown that nitrogen also influences the ordering quality of Ge QDs and that second order of Bragg spots are narrower and better visible for the film with 2% of nitrogen. Increase in the deposition temperature results in larger Ge QDs. Especially grows lateral radius of Ge QDs, Rl. It increases from 11.9 nm to 20.8 nm when the temperature changes from 300ºC to 500ºC. Germanium oxidation was studied using x-ray photoelectron spectroscopy and it was shown that germanium oxidation strongly influences optical properties of our thin film material. Combination of the mentioned parameters presents a powerful tool for control of the properties of the materials that are important for the optoelectronic applications.

Ge QDs ; Quantum efficiency ; QD lattices ; N-assisted deposition ; Spectral response

nije evidentirano