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 the 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 the structural and optical properties of the material and the self- assembled growth regime. Special attention was devoted to the oxidation of Ge quantum dots, and their effect on the optical properties of the material. It was shown that the presence of N affects the size of Ge QDs, their oxidation, and their optical properties. Deposition temperature and Ge content also affect Ge QD sizes and consequently bandgap and optical properties. Thus, the combination of the mentioned parameters presents a powerful tool for control of the properties of the material that are important for optoelectronic applications.