Synthesis of CdSe-CdS dot-in-rod core-shell nanostructures

• Grant number: 14/10736-7
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): September 15, 2014
• Effective date (End): July 09, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Laudemir Carlos Varanda
• Grantee: João Batista Souza Junior
• Supervisor abroad: Dmitri V. Talapin
• Home Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Local de pesquisa : University of Chicago, United States
• Associated to the scholarship: 12/02093-3 - Synthesis of Co@Au (superparamagnetics) and CdSe@Zn (quantum dots) core@shell nanostructures for applications as antineoplasia agents, BP.DR

Abstract

The semiconductor nanoparticles show size dependent optical and electronic properties that can be used in several technological applications, like light-emitting, photovoltaic, and thermoelectric devices. Thus, this project intend to explore synthesis of CdSe/CdS dot-in-rod core-shell nanostructures, alignment and incorporation of the nanocrystals into thin-film polarized emitters. Single- and multicomponent nanocrystal assemblies provide a powerful general platform for designing programmable solids with tailored electronic, magnetic, and optical properties. Unlike atomic and molecular crystals where atoms, lattice geometry, and interatomic distances are fixed entities, nanocrystal arrays represent ensembles of "designer atoms" with potential for tuning their electronic structure and transport properties. This research seeks to improve efficiency of LCD backlighting by using precisely-engineered and aligned inorganic CdSe/CdS dot-in-rod nanocrystals that absorb unpolarized- and re-emit linearly-polarized light with high color purity and near 100% quantum efficiency. The color of re-emitted light is determined by nanocrystal quantum confinement. Ideally, the absorbing and re-emitting material in this layer should absorb light in a wide spectral range and exhibit a large Stokes shift, meaning that the re-emission should be at a wavelength where the absorption of the material is small. Such an approach is attractive because it can provide substantial gain in backlight illumination efficiency by funneling all optical energy in a narrow spectral window without adding significant additional cost and manufacturing complexity. Realization of this potential requires careful control of the nanocrystal architecture and alignment, as well as a deep understanding of the photophysics of energy collection and conversion processes. This knowledge is also important for the progress of the regular project in Brazil and can collaborate for the academic evolution of the student. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CUNNINGHAM, PATRICK D.; SOUZA, JR., JOAO B.; FEDIN, IGOR; SHE, CHUNXING; LEE, BYEONGDU; TALAPIN, DMITRI V. Assessment of Anisotropic Semiconductor Nanorod and Nanoplatelet Heterostructures with Polarized Emission for Liquid Crystal Display Technology. ACS NANO, v. 10, n. 6, p. 5769-5781, JUN 2016. Web of Science Citations: 62.