Magneto-optical properties of ionic magnetic fluids: The effect of the nanoparticle surface passivation

2004 ◽  
Vol 1 (12) ◽  
pp. 3575-3578 ◽  
Author(s):  
P.C. Morais ◽  
P.P Gravina ◽  
A.F. Bakuzis ◽  
K. Skeff Neto ◽  
E.C.D. Lima
2021 ◽  
Vol 23 ◽  
pp. 100948
Author(s):  
Saif M.H. Qaid ◽  
Hamid M. Ghaithan ◽  
Bandar Ali Al-Asbahi ◽  
Abdullah S. Aldwayyan

2019 ◽  
Vol 48 (10) ◽  
pp. 6437-6445
Author(s):  
Eduardo F. Barbosa ◽  
Jaqueline A. Coelho ◽  
Edna R. Spada ◽  
Daniel R. B. Amorim ◽  
Livia M. C. Souza ◽  
...  

Author(s):  
Chan Beom Park ◽  
Yun Seop Shin ◽  
Yung Jin Yoon ◽  
Hyungsu Jang ◽  
Jung Geon Son ◽  
...  

Cs-based perovskite nanocrystals (PeNCs) have been considered to be superb emitters for perovskite light-emitting diodes (PeLEDs) due to their remarkable optoelectronic properties. Still, poor optical properties are mainly attributed to...


2021 ◽  
Author(s):  
Baharak Mehrdel ◽  
Ali Nikbakht ◽  
Azlan Abdul Aziz ◽  
Mahmood S. Jameel ◽  
Mohammed Ali Dheyab ◽  
...  

Abstract Upconversion (UC) of lanthanide-doped nanostructure has the unique ability to convert low energy infrared (IR) light to high energy photons, which has significant potential for energy conversion applications. This review concisely discusses the basic concepts and fundamental theories of lanthanide nanostructures, synthesis techniques, and enhancement methods of upconversion for photovoltaic and for near-infrared (NIR) photodetector application. In addition, a few examples of lanthanide-doped nanostructures with improved performance were discussed, with particular emphasis on upconversion emission enhancement using coupling plasmon. The use of UC materials has been shown to significantly improve the NIR light-harvesting properties of photovoltaic devices and photocatalytic materials. However, the inefficiency of UC emission also prompted the need for additional modification of the optical properties of UC material. This improvement entailed the proper selection of the host matrix and optimization of the sensitizer and activator concentrations, followed by subjecting the UC material to surface-passivation, plasmonic enhancement, or doping. As expected, improving the optical properties of UC materials can lead to enhanced efficiency of photodetectors and photovoltaic devices.


NANO ◽  
2009 ◽  
Vol 04 (04) ◽  
pp. 189-199 ◽  
Author(s):  
BENJAMIN A. BAKER ◽  
JONG HYUN CHOI

Various types of nanocrystals have extensively demonstrated significant advantages in magnetic, chemical, catalytic, and particularly optical properties. Still, some limitations prevent these properties from being utilized for improved biological imaging, therapeutics or micro/nano-optoelectronics. A recently emerging, facile approach employing oligonucleotide DNA or RNA for direct surface passivation of nanocrystals is showing promise to bridge the gap between functional potential and realization. Oligonucleotide capping can provide hydrophilic nature, target recognition capabilities, and enhanced cellular uptake for nanocrystals, with a simplified synthesis capable of both templating and functionalizing. We overview synthesis, properties, and applications of nucleic acid templated nanocrystals and contrast these with nanocrystals synthesized by more classical capping methods. Finally, we highlight areas of research in oligonucleotide templated nanocrystals that have been largely unexplored to date, where further investigations can provide many new insights.


2010 ◽  
Vol 1260 ◽  
Author(s):  
Anoop Gupta ◽  
Hartmut Wiggers

AbstractWhile silicon nanostructures acquire novel optical properties due to miniaturization, the stability of light emission is severely limited because of exciton trapping due to surface oxidation coming along with the formation of defects. Grafting of organic molecules on a hydrogen-terminated silicon surface via hydrosilylation provides a promising route to stabilize their surface against oxidation. In this communication, we report on the effect of surface passivation on the optical properties of freestanding silicon nanocrystals (Si-NCs). The surface functionalization of hydrogen-terminated Si-NCs with organic molecules was achieved via liquid phase hydrosilylation. We demonstrate that surface functionalization does not preserve the original emission of hydrogen-terminated Si-NCs. It is observed that the emission spectrum of green emitting hydrogen-terminated Si-NCs is red shifted after surface functionalization. We find that the direction of shift does not depend on the type of organic ligands and the reaction conditions, however, the amount of shift can be altered. The factors influencing the shift in the emission spectra of functionalized Si-NCs with respect to hydrogen-terminated samples are discussed.


2017 ◽  
Vol 127 ◽  
pp. 108-116 ◽  
Author(s):  
Anna Kosinova ◽  
Dong Wang ◽  
Eszter Baradács ◽  
Bence Parditka ◽  
Thomas Kups ◽  
...  

2008 ◽  
Vol 8 (3) ◽  
pp. 1165-1169 ◽  
Author(s):  
Baojiu Chen ◽  
Qingyu Meng ◽  
Haiyang Zhong ◽  
Jiashi Sun ◽  
Lihong Cheng ◽  
...  

Cubic nano-crystalline Y2O3:Eu3+ powders with different grain sizes were produced by chemical auto-combustion, and their structure, morphology, and fluorescent spectra were characterized. The quantum efficiency of the 5D0 level of Eu3+ was estimated, taking into account the energy transfer between Eu3+ ions located at C2 and S6 sites. Ag+ ions were introduced into the synthesis of the nanosized particles to modify the surface defects, resulting in increased emission intensity. These results indicated that the nanosized Y2O3:Eu3+ exhibits maximum internal quantum efficiency close to 90% after Ag+ ions are introduced into the synthesis of Y2O3:Eu3+. From the experimental results, it was concluded that the Ag+ ions are probably absorbed by the nanoparticle surface and do not enter the nanoparticle lattice. It was also found that the Ag+ ions can repair the surface defects and make the absorption of excitation light more efficient.


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