Understanding and control of the erbium non-radiative de-excitation processes in silicon

Abstract Erbium doping of silicon has recently emerged as a promising method to tailor the optical properties of Si towards the achievement of a light emission at 1.54 μm. In this paper we will review our recent work on this subject. In particular a detailed investigation of the non-radiative processes, competing with the radiative emission of Er in Si will be presented. Among these processes, an Auger de-excitation with the energy released to free carriers will be demonstrated to be extremely efficient, with an Auger coefficient CA∼4.4×10−13 cm3/s. Moreover, at temperatures above 100 K a phonon-assisted back-transfer decay process, characterized by an activation energy of 0.15 eV is seen to set in. This understanding of the physical properties competing with the radiative light emission allowed us to control them and obtain efficient room temperature luminescence. Two examples will be reported. It will be shown that by exciting Er within the depletion region of reverse biased p+–n+ Si diodes in the breakdown regime it is possible to avoid Auger quenching and to achieve high efficiency. Moreover, at the switch off of the diode, when the depletion region shrinks, the excited Er ions become suddenly embedded within the neutral heavily doped region of the device. In this region Auger de-excitation with free carriers sets in and quenches rapidly the luminescence. This allows to modulate the light signal at frequencies as high as a few MHz. Furthermore, the introduction of Er within Si nanocrystals is demonstrated to be a promising way to eliminate back-transfer processes by a widening of the bandgap while maintaining the full advantage of the efficient electron-hole mediated excitation present in Si. These data are presented and future perspective discussed.

[1]  Polman,et al.  Temperature dependence and quenching processes of the intra-4f luminescence of Er in crystalline Si. , 1994, Physical review. B, Condensed matter.

[2]  Donor activity of ion-implanted erbium in silicon , 1997 .

[3]  Wilson,et al.  Optically active erbium centers in silicon. , 1996, Physical review. B, Condensed matter.

[4]  A. Suchocki,et al.  A method of excitation profiling in high‐field electroluminescence , 1981 .

[5]  J. Poate,et al.  Room‐temperature sharp line electroluminescence at λ=1.54 μm from an erbium‐doped, silicon light‐emitting diode , 1994 .

[6]  S. Tohno,et al.  1.54 μm photoluminescence of in situ erbium‐oxygen co‐doped silicon films grown by ion‐beam epitaxy , 1995 .

[7]  S. Tohno,et al.  Electroluminescence of erbium-doped silicon films as grown by ion beam epitaxy , 1997 .

[8]  F. Priolo,et al.  The effects of oxygen and defects on the deep‐level properties of Er in crystalline Si , 1995 .

[9]  F. Priolo,et al.  Optical activation and excitation mechanisms of Er implanted in Si. , 1993, Physical review. B, Condensed matter.

[10]  A. Axmann,et al.  1.54‐μm luminescence of erbium‐implanted III‐V semiconductors and silicon , 1983 .

[11]  Alberto Carnera,et al.  Room‐temperature electroluminescence from Er‐doped crystalline Si , 1994 .

[12]  Sebania Libertino,et al.  The erbium‐impurity interaction and its effects on the 1.54 μm luminescence of Er3+ in crystalline silicon , 1995 .

[13]  Langer,et al.  Auger effect in the Mn2+ luminescence of CdF2:(Mn,Y) crystals. , 1989, Physical review. B, Condensed matter.

[14]  I. Buyanova,et al.  Er/O and Er/F doping during molecular beam epitaxial growth of Si layers for efficient 1.54 μm light emission , 1997 .

[15]  A. Taguchi,et al.  Energy Transfer in Rare-Earth-Doped III-V Semiconductors , 1992 .

[16]  G. Hendorfer,et al.  On the local structure of optically active Er centers in Si , 1995 .

[17]  Salvatore Coffa,et al.  Mechanism and performance of forward and reverse bias electroluminescence at 1.54 μm from Er-doped Si diodes , 1997 .

[18]  L. Canham.  Progress Toward Crystalline-Silicon-Based Light-Emitting Diodes , 1993 .

[19]  G. V. Hansson,et al.  Room temperature 1.54 μm light emission of erbium doped Si Schottky diodes prepared by molecular beam epitaxy , 1997 .

[20]  F. Priolo,et al.  High efficiency and fast modulation of Er‐doped light emitting Si diodes , 1996 .

[21]  A. Polman,et al.  Incorporation of high concentrations of erbium in crystal silicon , 1993 .

[22]  L. Kimerling,et al.  The mechanisms of electronic excitation of rare earth impurities in semiconductors , 1993 .

[23]  Gerhard Abstreiter,et al.  INFLUENCE OF THE ERBIUM AND OXYGEN CONTENT ON THE ELECTROLUMINESCENCE OF EPITAXIALLY GROWN ERBIUM-DOPED SILICON DIODES , 1997 .

[24]  F. Priolo,et al.  Electrical and optical characterization of Er‐implanted Si: The role of impurities and defects , 1993 .

[25]  Gerhard Abstreiter,et al.  Electroluminescence of erbium–oxygen‐doped silicon diodes grown by molecular beam epitaxy , 1996 .

[26]  Zheng,et al.  Electroluminescence of erbium-doped silicon. , 1996, Physical review. B, Condensed matter.

[27]  A. Lacaita,et al.  Direct evidence of impact excitation and spatial profiling of excited Er in light emitting Si diodes , 1998 .

[28]  P. H. Citrin,et al.  Local structure of 1.54‐μm‐luminescence Er3+ implanted in Si , 1992 .

[29]  Salvatore Coffa,et al.  Excitation and nonradiative deexcitation processes of Er 3 + in crystalline Si , 1998 .

[30]  Jurgen Michel,et al.  Impurity enhancement of the 1.54‐μm Er3+ luminescence in silicon , 1991 .

[31]  L. Canham.  Silicon optoelectronics at the end of the rainbow , 1992 .