Infrared Luminescence in Er and Er+O Implanted 6H SiC

Abstract

Photoluminescence in the neighbourhood of 1.54 μm due to the 4l13/2 -4 I15/2 intra-4f-shell transitions of Er3+ ions in 6Η SiC is studied. Effects of oxygen coimplantation is also investigated. No difference in the photoluminescence spectra of Er only and Er+O implanted SiC was found. It is concluded that the emission around 1.54 μm in SiC:Er originates from erbium-oxygen complexes, which are formed as a result of thermal annealing.PACS numbers: 61.72. Ww, The research interest in erbium doped semiconductors is growing rapidly [1], because Er3+ ions exhibit luminescence around 1.54 μm originating in the 4/i3/2 -4 Ι 1 5 / 2 e l e c t r o n i c t r a n s i t i o n s w i t h i n t h e 4 f s h e l l . T h i s w a v e l e n g t h c o r r e s p o n d s t o the minimum absorption of silica-based fibers, making Er-doped light sources and amplifiers promising for applications in optical telecommunications.While many Er-doped semiconductors have been studied to date, only a few reveal 1.54 μm emission at 300 K. Favennec et al. [2] have observed that the quenching processes of the 4f-4f photoluminescence (PL) of Er3+ ions become less effective with the increase of the semiconductor band gap. Attempts to increase the emission efficiency of erbium in Si and GaAs with oxygen codoping were quite successful [3][4][5], however, the intensity of light from Er+O doped Si and GaAs electroluminescent diodes has been still too low for any practical applications. Once again the relatively narrow band gaps of semiconductors, particularly in case of Si, appeared to be the dominant parameter affecting excitation and relaxation of the 4f-shell. All these observations point to the necessity to use wide band gap semiconductors, like SiC, GaN, AlN, etc., as hosts, to receive the efficient 4f-4f (879)

Bhabha scattering with radiated gravitons at linear colliders

“…This tames the collinear singularities arising from t-channel photon exchange. At the same time, it also ensures that any background effects from beamstrahlung are mostly eliminated [14].…”