Core/Shell CdSe/CdS Bone-Shaped Nanocrystals with a Thick and Anisotropic Shell as Optical Emitters

Autor: Iwan Moreels, Balaji Dhanabalan, Beatriz Martín-García, Anatolii Polovitsyn, Milan Palei, Francesco Di Stasio, Mirko Prato, Andrea Castelli, Liberato Manna, Alice Scarpellini, Milena P. Arciniegas, Vincenzo Caligiuri, Rosaria Brescia, Roman Krahne
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Amplified spontaneous emission
Photoluminescence
Materials science
NANOPLATELETS
shell nanocrystals
Shell (structure)
FOS: Physical sciences
Physics::Optics
02 engineering and technology
QUANTUM DOTS
010402 general chemistry
01 natural sciences
amplified spontaneous emission
Condensed Matter::Materials Science
COLLOIDAL NANOCRYSTALS
Physics - Chemical Physics
ROD NANOCRYSTALS
HETEROSTRUCTURES
Physics::Atomic and Molecular Clusters
SEMICONDUCTOR NANOCRYSTALS
CHALCOGENIDES
random lasing
Chemical Physics (physics.chem-ph)
business.industry
dual emission
core
Heterojunction
021001 nanoscience & nanotechnology
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
AUGER RECOMBINATION
Atomic and Molecular Physics
and Optics
3. Good health
0104 chemical sciences
Electronic
Optical and Magnetic Materials
Nanocrystal
Physics and Astronomy
Quantum dot
SEEDED GROWTH
Optoelectronics
Charge carrier
branched heterostructures
0210 nano-technology
business
seeded-growth synthesis
EMISSION
Lasing threshold
Zdroj: ADVANCED OPTICAL MATERIALS
Advanced Optical Materials
ISSN: 2195-1071
Popis: Colloidal core/shell nanocrystals are key materials for optoelectronics, enabling control over essential properties via precise engineering of the shape, thickness, and crystal lattice structure of their shell. Here, we apply the growth protocol for CdS branched nanocrystals on CdSe nanoplatelet seeds and obtain bone-shaped heterostructures with a highly anisotropic shell. Surprisingly, the nanoplatelets withstand the high growth temperature of 350 {\deg}C and we obtain structures with a CdSe nanoplatelet core that is overcoated by a shell of cubic CdS, on top of which tetrahedral CdS structures with hexagonal lattice are formed. These complex core/shell nanocrystals show a bandedge emission around 657 nm with a photoluminescence quantum yield of ca. 42 % in solution, which is also retained in thin films. Interestingly, the nanocrystals manifest simultaneous red and green emission, and the relatively long wavelength of the green emission indicates charge recombination at the cubic/hexagonal interface of the CdS shell. The nanocrystal films show amplified spontaneous emission, random lasing, and distributed feedback lasing when the material is deposited on suitable gratings. Our work stimulates the design and fabrication of more exotic core/shell heterostructures where charge carrier delocalization, dipole moment, and other optical and electrical properties can be engineered.
Comment: 26 pages, 6 figures, 1 table
Databáze: OpenAIRE
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