scholarly journals Properties of Anti-Stokes Photoluminescence and Ideal Laser Cooling Performance in Yb-Doped Yttrium Aluminum Garnet Thin Film

2020 ◽  
Vol 69 (10) ◽  
pp. 727-732
Author(s):  
Yuta NAKAYAMA ◽  
Nozomu NAKAGAWA ◽  
Yukihiro HARADA ◽  
Takashi KITA
Keyword(s):  
Thin Film ◽  
Laser Cooling ◽  
Yttrium Aluminum Garnet ◽  
Cooling Performance ◽  
Yttrium Aluminum ◽  
Anti Stokes

Advances in Laser Cooling of Solids

2006 ◽  
Vol 129 (1) ◽  
pp. 3-10 ◽  
Author(s):  
X. L. Ruan ◽  
M. Kaviany
Keyword(s):  
Laser Cooling ◽  
Nonradiative Recombination ◽  
Rapid Progress ◽  
Cooling Process ◽  
Theoretical Limit ◽  
Rare Earth Ion ◽  
Cooling Performance ◽  
Theoretical Predictions ◽  
Anti Stokes ◽  
Near Future

We review the progress on laser cooling of solids. Laser cooling of ion-doped solids and semiconductors is based on the anti-Stokes fluorescence, where the emitted photons have a mean energy higher than that of the absorbed photons. The thermodynamic analysis shows that this cooling process does not violate the second law, and that the achieved efficiency is much lower than the theoretical limit. Laser cooling has experienced rapid progress in rare-earth-ion doped solids in the last decade, with the temperature difference increasing from 0.3to92K. Further improvements can be explored from the perspectives of materials and structures. Also, theories need to be developed, to provide guidance for searching enhanced cooling performance. Theoretical predictions show that semiconductors may be cooled more than ion-doped solids, but no success in bulk cooling has been achieved yet after a few attempts (due to the fluorescence trapping and nonradiative recombination). Possible solutions are discussed, and net cooling is expected to be realized in the near future.

scholarly journals Fabrication of GaN-Based White Light-Emitting Diodes on Yttrium Aluminum Garnet-Polydimethylsiloxane Flexible Substrates

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Lung-Chien Chen ◽  
Wen-Wei Lin ◽  
Jun-Wei Chen
Keyword(s):  
Thin Film ◽  
White Light ◽  
Yttrium Aluminum Garnet ◽  
Light Emitting Diode ◽  
Flexible Substrates ◽  
Light Emitting ◽  
White Leds ◽  
Yttrium Aluminum ◽  
Lift Off ◽  
White Light Emitting Diodes

This study concerns the characteristics of white GaN-based light-emitting diode (LED) on flexible substrates. The thin film GaN-based blue LEDs were directly transferred from sapphire onto the flexible polydimethylsiloxane (PDMS) substrates by laser lift-off (LLO) process. The PDMS substrates were incorporated 10–40% cerium doped yttrium aluminum garnet phosphor, YAG:Ce3+, and formed the GaN-based white LEDs. The white LEDs prepared by the GaN-based LEDs on the YAG-PDMS substrates reveal one peak at 470 nm corresponding to the emission of the GaN-based LED and a broadband included five weak peaks caused by YAG:Ce3+phosphors.

Yag Single Crystals for Scintillators of Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 166-167
Author(s):  
M. Hibino ◽  
K. Irie ◽  
R. Autrata ◽  
P. schauer
Keyword(s):  
Single Crystals ◽  
Yttrium Aluminum Garnet ◽  
Light Guide ◽  
Detection System ◽  
Polished Surface ◽  
Detective Quantum Efficiency ◽  
Backscattered Electrons ◽  
Electron Detection ◽  
Yttrium Aluminum ◽  
Phosphor Screens

Although powdered phosphor screens are usually used for scintillators of STEM, it has been found that the phosphor screen of appropriate thickness should be used depending on the accelerating voltage, in order to keep high detective quantum efficiency. 1 It has been also found that the variation in sensitivity, due to granularity of phosphor screens, makes the measurement of fine electron probe difficult and that the sensitivity reduces with electron irradiation specially at high voltages.In order to find out a preferable scintillator for STEM, single crystals of YAG (yttrium aluminum garnet), which are used for detecting secondary and backscattered electrons in SEM were investigated and compared with powdered phosphor screens, at the accelerating voltages of 100kV and 1 MV. A conventional electron detection system, consisting of scintillator, light guide and PMT (Hamamatsu Photonics R268) was used for measurements. Scintillators used are YAG single crystals of 1.0 to 3.2mm thicknesses (with surfaces matted for good interface to the light guide) and of 0.8mm thickness (with polished surface), and powdered P-46 phosphor screens of 0.07mm and 1.0mm thicknesses for 100kV and 1MV, respectively. Surfaces on electron-incidence side of all scintillators are coated with reflecting layers.

Anti-Stokes Luminescence of Bulk and Thin-Film β-InSe under Infrared Optical Excitation

JETP Letters ◽  
2020 ◽  
Vol 112 (3) ◽  
pp. 145-149
Author(s):  
S. N. Nikolaev ◽  
M. A. Chernopitsskii ◽  
V. S. Bagaev ◽  
V. S. Krivobok
Keyword(s):  
Thin Film ◽  
Optical Excitation ◽  
Anti Stokes
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