High resolution imaging analysis of CdSe/ZnS core–shell quantum dots (QDs) using Cs-corrected HR-TEM/STEM

• Published in: Journal of materials science. Materials in electronics Vol. 24; no. 10; pp. 3744 - 3748
• Main Authors: Shin, Huiyoun, Jang, Dongseon, Jang, Youngil, Cho, Myungju, Park, Kyuho
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2013; Springer; Springer Nature B.V
• Subjects: Applied sciences; Cadmium selenides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; High resolution; Imaging; Intermetallics; Materials; Materials Science; Metals. Metallurgy; Nanocrystals; Nanoscale materials and structures: fabrication and characterization; Optical and Electronic Materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Production techniques; Quantum confinement; Quantum dots; Semiconductors; Surface treatment; Transmission electron microscopy; Graphene Membrane; Graphene Monolayer; Transmission Electron Microscope Specimen; Stem HAADF Image; CdSe Core; Quantum confinement; Tunable circuit; Particle size; High resolution; Quantum dot; Photoluminescence; Coatings; Zinc sulfide; Energy gap; Light emission; Imaging; Nanodot; Copper; Scanning transmission electron microscopy; Nanocrystal; Ultrathin films; II-VI compound; Core shell structure; Quantum yield; Narrow band; Carbon; Coated material; Cadmium selenides; Thickness; Transmission electron microscopy; Graphene; High efficiency; Zero band gap semiconductors; Drying
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-013-1312-1

CdSe/ZnS core–shell structured nano-crystal quantum dots (QDs) are ideal candidates for light-emission applications due to their high quantum efficiency, narrow-band, and particle-size-tunable photoluminescence. In particular, their small size results in the quantum confinement of semiconductor nano-crystals, which widens their energy gaps. In general, high resolution imaging analyses of QDs using a transmission electron microscope are very difficult due to their significantly small size. Successful imaging depends on the capabilities of TEM equipment and the contrast of the QDs sample relative to the supporting film. In this work, all imaging analyses were performed on a TEM equipped with a probe Cs corrector. The samples for observing QDs were prepared by drying each QDs solution on a lacey carbon Cu (300 mesh) grid previously coated with an ultra-thin graphene monolayer (thickness = 0.3 nm), due to the need to minimize the effect of the supported film.