Size Control of Mesoscale Aqueous Assemblies of Quantum Dots and Block Copolymers

Langmuir ◽  
2007 ◽  
Vol 23 (2) ◽  
pp. 868-878 ◽  
Author(s):  
Huda Yusuf ◽  
Whan-Gi Kim ◽  
Dong Hoon Lee ◽  
Yunyong Guo ◽  
Matthew G. Moffitt
Keyword(s):  
Quantum Dots ◽  
Block Copolymers ◽  
Size Control

scholarly journals InN Quantum Dots by Metalorganic Chemical Vapor Deposition for Optoelectronic Applications

2021 ◽  
Vol 8 ◽  
Author(s):  
Caroline E. Reilly ◽  
Stacia Keller ◽  
Shuji Nakamura ◽  
Steven P. DenBaars
Keyword(s):  
Quantum Dots ◽  
Chemical Vapor Deposition ◽  
Recent Work ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Near Infrared ◽  
Optoelectronic Devices ◽  
Size Control ◽  
Chemical Vapor ◽  
Metalorganic Chemical

This review will cover recent work on InN quantum dots (QDs), specifically focusing on advances in metalorganic chemical vapor deposition (MOCVD) of metal-polar InN QDs for applications in optoelectronic devices. The ability to use InN in optoelectronic devices would expand the nitrides system from current visible and ultraviolet devices into the near infrared. Although there was a significant surge in InN research after the discovery that its bandgap provided potential infrared communication band emission, those studies failed to produce an electroluminescent InN device in part due to difficulties in achieving p-type InN films. Devices utilizing InN QDs, on the other hand, were hampered by the inability to cap the InN without causing intermixing with the capping material. The recent work on InN QDs has proven that it is possible to use capping methods to bury the QDs without significantly affecting their composition or photoluminescence. Herein, we will discuss the current state of metal-polar InN QD growth by MOCVD, focusing on density and size control, composition, relaxation, capping, and photoluminescence. The outstanding challenges which remain to be solved in order to achieve InN infrared devices will be discussed.

scholarly journals Top-Down N-Doped Carbon Quantum Dots for Multiple Purposes: Heavy Metal Detection and Intracellular Fluorescence

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2249
Author(s):  
Francesca Limosani ◽  
Elvira Maria Bauer ◽  
Daniele Cecchetti ◽  
Stefano Biagioni ◽  
Viviana Orlando ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Reaction Times ◽  
Size Control ◽  
Carbon Quantum Dots ◽  
Cell Nuclei ◽  
Top Down ◽  
Hek 293 ◽  
Metal Ion Detection ◽  
Intracellular Fluorescence

In the present study, we successfully synthesized N-doped carbon quantum dots (N-CQDs) using a top-down approach, i.e., hydroxyl radical opening of fullerene with hydrogen peroxide, in basic ambient using ammonia for two different reaction times. The ensuing characterization via dynamic light scattering, SEM, and IR spectroscopy revealed a size control that was dependent on the reaction time, as well as a more pronounced -NH2 functionalization. The N-CQDs were probed for metal ion detection in aqueous solutions and during bioimaging and displayed a Cr3+ and Cu2+ selectivity shift at a higher degree of -NH2 functionalization, as well as HEK-293 cell nuclei marking.

Size-Controlled Microwave-Assisted Synthesis of Water-Dispersible Cd(Se,S) Quantum Dots for Potential Biological Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
E. Calderón-Ortiz ◽  
S. Bailón-Ruiz ◽  
L. Alamo-Nole ◽  
J. Rodriguez-Orengo ◽  
O. Perales-Perez
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Quantum Confinement Effect ◽  
Reactive Oxygen Species Generation ◽  
Size Control ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

Tuning photocurrent response through size control of CdTe quantum dots sensitized solar cells

Solar Energy ◽  
2013 ◽  
Vol 88 ◽  
pp. 137-143 ◽  
Author(s):  
Ali Badawi ◽  
N. Al-Hosiny ◽  
Said Abdallah ◽  
S. Negm ◽  
H. Talaat
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Size Control ◽  
Cdte Quantum Dots ◽  
Photocurrent Response ◽  
Sensitized Solar Cells

Binary Self-Assembly of Conjugated Block Copolymers and Quantum Dots at the Air–Liquid Interface into Ordered Functional Nanoarrays

2019 ◽  
Vol 11 (31) ◽  
pp. 28538-28545 ◽  
Author(s):  
Saejin Oh ◽  
Myungjae Yang ◽  
Seulki Kang ◽  
Sung-Hee Chung ◽  
Jean Bouffard ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Block Copolymers ◽  
Self Assembly ◽  
Liquid Interface ◽  
Air Liquid Interface

scholarly journals Fractionation of block copolymers for pore size control and reduced dispersity in mesoporous inorganic thin films

Nanoscale ◽  
2020 ◽  
Vol 12 (35) ◽  
pp. 18455-18462
Author(s):  
Alberto Alvarez-Fernandez ◽  
Barry Reid ◽  
Jugal Suthar ◽  
Swan Yia Choy ◽  
Maximiliano Jara Fornerod ◽  
...  
Keyword(s):  
Thin Films ◽  
Block Copolymers ◽  
Pore Size ◽  
Size Control ◽  
Widespread Application ◽  
Inorganic Thin Films ◽  
Pore Size Control

Inorganic mesoporous coatings find widespread application. In many cases, control over the pore dimensions is of paramount importance. To this end, we establish a powerful route to pore size and dispersity control.

Stable aqueous colloids of ZnS quantum dots prepared using double hydrophilic block copolymers

2013 ◽  
Vol 37 (2) ◽  
pp. 508-514 ◽  
Author(s):  
Konstantin Tarasov ◽  
Dania Houssein ◽  
Mathias Destarac ◽  
Nathalie Marcotte ◽  
Corine Gérardin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Block Copolymers ◽  
Double Hydrophilic Block Copolymers

Modeling and size control of CsPbBr3 perovskite quantum dots

2020 ◽  
Author(s):  
Niranjan Sitapure ◽  
Tian Qiao ◽  
Dong Hee Son ◽  
Joseph Sang-Il Kwon
Keyword(s):  
Quantum Dots ◽  
Size Control ◽  
Perovskite Quantum Dots
Sign in / Sign up

Export Citation Format

Share Document