1.54μm photoluminescence of Er-doped GeOx thin films

International audienceAmorphous Er-doped GeO x alloys were prepared by evaporation on substrates maintained at 100°C. Photoluminescence experiments were carried out in the visible and near-infrared ranges. The Er-related peak was observed at 1.54 m at room temperature in the as deposited samples. The PL of erbium is characterized by a weak temperature quenching and by a decay time in the millisecond range. The luminescence of Er is a decreasing function of the annealing temperature. Undoped GeO x layers showed a PL band at 800 nm, attributed to defects states, which disappeared when Er is introduced. The intense Er-related luminescence was assigned to an indirect excitation process from defects states to Er ions

A Hybrid model for the origin of photoluminescence from Ge nanocrystals in SiO2_2 matrix

In spite of several articles, the origin of visible luminescence from germanium nanocrystals in SiO$_2$ matrix is controversial even today. Some authors attribute the luminescence to quantum confinement of charge carriers in these nanocrystals. On the other hand, surface or defect states formed during the growth process, have also been proposed as the source of luminescence in this system. We have addressed this long standing query by simultaneous photoluminescence and Raman measurements on germanium nanocrystals embedded in SiO$_2$ matrix, grown by two different techniques: (i) low energy ion-implantation and (ii) atom beam sputtering. Along with our own experimental observations, we have summarized relevant information available in the literature and proposed a \emph{Hybrid Model} to explain the visible photoluminescence from nanocrystalline germanium in SiO$_2$ matrix.Comment: 23 pages, 8 figure

Influence of the multilayer system on the structure and photoluminescence of GeOx thin films

  Amorphous GeOx/SiO2 multilayers (