Blue emission of Ge nanocrystals prepared by thermal decomposition

We report here a simple synthesis method for monodisperse Ge nanocrystals by thermal decomposition of precursor TOG at 360 deg. C, which is obtained by a reaction of GeCl4 with oleylamine at room temperature. The effect of refluxing time on the average dimension of Ge nanocrystals is discussed. Fundamental characterizations including HRTEM and XRD were performed on these Ge nanocrystals. FTIR, DSC and TG were used to explain the mechanism of formation of Ge nanocrystals by thermal decomposition of TOG. Ge nanocrystals with average grain sizes clearly exhibit blue emission, which might result from the hydrocarbon absorbed on the surface Ge nanocrystals, the amorphous oxide layer on the surface of Ge nanocrystals and/or defects in Ge nanocrystals