Coupling and Cooperative Up-conversion Coefficients in Er-doped Si Nanocrystals

2003 ◽  
Vol 770 ◽  
Author(s):  
Domenico Pacifici ◽  
Giorgia Franzò ◽  
Fabio Iacona ◽  
Francesco Priolo
Keyword(s):  
Steady State ◽  
Energy Level ◽  
Energy Level Scheme ◽  
Time Resolved ◽  
A Value ◽  
Si Nanocrystals ◽  
Si Nanocrystal ◽  
Conversion Coefficients ◽  
Quantitative Understanding ◽  
Er Doped

AbstractIn the present work, a quantitative understanding of the Er-doped Si nanocrystals interaction is reported. We present a model based on an energy level scheme taking into account the coupling between each Si nanocrystal and the neighboring Er ions. By fitting the steady state and time resolved luminescence signals at both the 1.54 and 0.98 μm Er lines we were able to determine a value of 3×10-15 cm3 s-1 for the coupling coefficient. Moreover, a strong cooperative up-conversion mechanism, active between two excited Er ions and characterized by a coefficient of 7×10-17 cm3 s-1, will be shown to be active in the system, demonstrating that each Si nanocrystal can actually excite more than one Er ion.

Rare-earth doped Si nanostructures for Microphotonics

2004 ◽  
Vol 817 ◽  
Author(s):  
D. Pacifici ◽  
G. Franzò ◽  
F. Iacona ◽  
A. Irrera ◽  
S. Boninelli ◽  
...  
Keyword(s):  
Rare Earth ◽  
Light Emission ◽  
Rare Earth Ions ◽  
Energy Level Scheme ◽  
Electroluminescent Devices ◽  
A Value ◽  
Si Nanocrystals ◽  
Emission Yield ◽  
Si Nanostructures ◽  
Rare Earth Doped

AbstractIn the present paper, we will review our work on rare-earth doped Si nanoclusters. The samples have been obtained by implanting the rare-earth (e.g. Er) in a film containing preformed Si nanocrystals. After the implant, samples have been treated at 900°C for 1h. This annealing temperature is not enough to re-crystallize all of the amorphized Si clusters. However, even if the Si nanoclusters are in the amorphous phase, they can still efficiently transfer the energy to nearby rare-earth ions. We developed a model for the Si nanoclusters-Er system, based on an energy level scheme taking into account the coupling between each Si nanocluster and the neighboring Er ions. By fitting the data, we were able to determine a value of 3×10−15 cm3 s−1 for the Si nanocluster-Er coupling coefficient. Moreover, a strong cooperative up-conversion mechanism between two excited Er ions and characterized by a coefficient of 7×10−17 cm3 s−1, is shown to be active in the system, demonstrating that more than one Er ion can be excited by the same nanocluster. We show that the overall light emission yield of the Er related luminescence can be enhanced by using higher concentrations of very small nanoaggregates. Eventually, electroluminescent devices based on rare-earth doped Si nanoclusters will be demonstrated.

SPECIFIC HEAT OF ErNi5 AND DyNi5

1993 ◽  
Vol 07 (01n03) ◽  
pp. 379-382 ◽  
Author(s):  
R. J. RADWAŃSKI ◽  
N. H. KIM-NGAN ◽  
F. E. KAYZEL ◽  
J. J. M. FRANSE
Keyword(s):  
Rare Earth ◽  
Energy Level ◽  
Specific Heat ◽  
Level Scheme ◽  
Exchange Interactions ◽  
Electron Subsystem ◽  
Energy Level Scheme ◽  
A Value ◽  
Schottky Type ◽  
The Rare Earth

The specific heat of DyNi 5 measured on a single-crystalline specimen in the temperature interval from 1.5 K to 250 K has been analyzed in terms of two electronic subsystems. The conduction-electron subsystem is characterized by a value of the Sommerfeld coefficient γ of 36 mJ/K 2 mol . The contribution of the rare-earth subsystem to the specific heat shows a λ-type of peak at T c and above T c a Schottky-type of peak. The rare-earth contribution is well described within a single-ion Hamiltonian that includes the CEF and exchange interactions of the R 3+ ions. The CEF interactions in ErNi 5 and DyNi 5 have been compared and a very similar charge multipolar distribution around the R 3+ ions is found. The energy level scheme of these Kramers ions with J = 15/2 is derived.

pH Effects on the Spectroscopic and Photochemical Behavior of Enoxacin: A Steady-State and Time-Resolved Study

1998 ◽  
Vol 67 (2) ◽  
pp. 167 ◽  
Author(s):  
S. Sortino ◽  
G. De Guidi ◽  
S. Giuffrida ◽  
S. Monti ◽  
A. Velardita
Keyword(s):  
Steady State ◽  
Ph Effects ◽  
Time Resolved ◽  
Photochemical Behavior

scholarly journals Energy level scheme ofInAs/InxGa1−xAs/GaAsquantum-dots-in-a-well infrared photodetector structures

2010 ◽  
Vol 82 (3) ◽  
Author(s):  
L. Höglund ◽  
K. F. Karlsson ◽  
P. O. Holtz ◽  
H. Pettersson ◽  
M. E. Pistol ◽  
...  
Keyword(s):  
Energy Level ◽  
Level Scheme ◽  
Infrared Photodetector ◽  
Energy Level Scheme

scholarly journals Ground- and excited-state characteristics in photovoltaic polymer N2200

RSC Advances ◽  
2021 ◽  
Author(s):  
Guanzhao Wen ◽  
Xianshao Zou ◽  
Rong Hu ◽  
Jun Peng ◽  
Zhifeng Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Steady State ◽  
Excited States ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Time Dependent ◽  
Functional Theory ◽  
Time Resolved ◽  
Dependent Density

Ground- and excited-states properties of N2200 have been studied by steady-state and time-resolved spectroscopies as well as time-dependent density functional theory calculations.

Sign in / Sign up

Export Citation Format

Share Document