Erbium Luminescence in Silicon

Abstract

We report on high resolution photoluminescence investigations of Er-implanted Si and demonstrate the variety of Er centers or complexes with impuritles and native Si-defects formed depending on the processing parameters. These centers are shown to differ in the efficiency of excitation transfer as well as high temperature photoluminescence yield. The mechanisms responsible for the photoluminescence quenching at different temperature regimes are discussed.PACS numbers: 78.55.Hx IntroductionThe interest in Er-doped silicon as a potential infrared light source is closely connected with the development of fiber optics communication systems. The transition between the two lowest spin-orbit split levels of the trivalent erbium ion occurs namely at a wavelength about 1.54 μm, which coincides with the minimum loss as well as minimum dispersion of silica based optical fibers [1]. Moreover, in contrast to near band gap lasers based on III-V compounds, the emission wave-length is temperature stable, which is of great importance in terrestrial applications. The ultimate goal is to obtain an Er-activated light source on silicon, which would open the way to fast intra-and inter-chip optical data transfer.Silicon is a material with the most mature integration processing technology, however, due to its indirect energy gap the probability of optical transitions is very low, which makes it unsuitable for optoelectronic applications. Despite the many attempts to relax the momentum conservation rules for interband transitions, such as zone folding or interface scattering in Si-Ge superlattices, the results are far from satisfactory. The most promising alternative path is, therefore, doping of silicon with luminescent impurities, such as erbium. Such a system is expected to combine the ultra sharp, atomic-like emission originating from intra-4f-shell transitions with the efficient pumping via electrons and holes. It is thus not surprising that the optical activity of Er in Si has achieved a lot of attention recently [2][3][4][5][6][7][8][9][10][11][12].

Structural and Optical Analysis of RE³⁺: LiNbO₃ Ceramic Powders

“…It has got unique piezoelectric, optical and photoelastic properties [16][17][18][19][20][21][22][23][24][25][26][27]. LiNbO 3 has been found to be a special lattice in which three similar sites could be found for cationic impurities, without distorting the main C 3 local symmetry: Li + , Nb 5+ and structural vacancy sites [28][29][30].…”