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 |
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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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