Electronic Mechanisms of Excitation of Rare-Earth Luminescence in Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
I. N. Yassievich
Keyword(s):  
Rare Earth ◽  
Electronic Excitation ◽  
Electron System ◽  
Rare Earth Ions ◽  
Impact Excitation

ABSTRACTTwo ways of electronic excitation for f-electron system of rare-earth ions in silicon are considered: impact excitation and Auger excitation. The probabilities of these processes are calculated.

Nature of the transfer of the electronic excitation energy from Cr3+to rare-earth ions in garnet crystals

1995 ◽  
Vol 25 (8) ◽  
pp. 729-734 ◽  
Author(s):  
Tasoltan T Basiev ◽  
Yu V Orlovskii ◽  
V G Ostroumov ◽  
Yu S Privis ◽  
Ivan A Shcherbakov
Keyword(s):  
Rare Earth ◽  
Excitation Energy ◽  
Electronic Excitation ◽  
Rare Earth Ions ◽  
Electronic Excitation Energy

MOS Light Emitting Devices Based on Rare-Earth Ion Implantation

2008 ◽  
Vol 590 ◽  
pp. 117-138 ◽  
Author(s):  
L. Rebohle ◽  
Wolfgang Skorupa
Keyword(s):  
Rare Earth ◽  
Ion Implantation ◽  
Indium Tin Oxide ◽  
Power Efficiency ◽  
Light Emission ◽  
Rare Earth Ions ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Hot Electron ◽  
Rare Earth Ion

In this article we will give an overview of our work devoted to Si-based light emission which was done in the last years. Si-based light emitters were fabricated by ion implantation of rare earth elements into the oxide layer of a conventional MOS structure. Efficient electroluminescence was obtained for the wavelength range from UV to the visible by using a transparent top electrode made of indium-tin oxide. In the case of Tb-implantation the best devices reach an external quantum efficiency of 16 % which corresponds to a power efficiency in the order of 0.3 %. The properties of the microstructure, the IV characteristics and the electroluminescence spectra were evaluated. The electroluminescence was found to be caused by hot electron impact excitation of rare earth ions, and the electric phenomena of charge transport, luminescence centre excitation, quenching and degradation are explained in detail.

Ion Implanted Er and Tb in SiO2 for Electroluminescence in MOS Diodes

2000 ◽  
Vol 647 ◽  
Author(s):  
Ch. Buchal ◽  
S. Coffa ◽  
S. Wang ◽  
R. Carius
Keyword(s):  
Rare Earth ◽  
Electric Fields ◽  
Room Temperature ◽  
Rare Earth Ions ◽  
Oxide Semiconductor ◽  
Impact Excitation ◽  
Hot Electron ◽  
Experimental Proof ◽  
Light Generation ◽  
Mos Structures

AbstractEfficient infra-red and visible electroluminescence(EL) has been obtained from implanted rare earth ions in the SiO2 of a silicon-metal-oxide-semiconductor (MOS) diode structure at room temperature. The rare earth ions are excited by the direct impact of hot electrons tunneling through the oxide at electric fields larger than 6 MV/cm. The internal quantum efficiencies of Er and Tb implanted MOS diodes are estimated to be 10 % and 3 %, respectively. The hgh quantum efficiency is due to the high impact excitation cross-section of more than 10− 15cm2. These observations on MOS structures are an experimental proof for efficient light generation by hot electron impact.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

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