Structural and optical properties of Ge nanocrystals embedded in Al2O3

The authors are grateful to Prof. R. Correia (Univ. de Aveiro) for help in performing the Raman experimental work. Accepted version (9 January 2007)Ge nanocrystals (NCs) embedded in aluminum oxide were grown by RF-magnetron sputtering. Raman, high resolution transmission electron microscopy (HRTEM), selected area diffraction (SAD), and X-ray diffraction (XRD) techniques confirmed good cristallinity of the NCs from samples annealed at 800 °C. The average NC size was estimated to be around 7 nm. Photoluminescence (PL) measurements show an emission related to the NCs. The temperature dependence of the PL confirms the confinement phenomenon in the Ge NCs.Project number POCTI/FIS/56930/2004 and STRP 505285-1 SEMINANO.FCT grant SFRH/BPD/11650/2002