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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Assessment of Anisotropic Semiconductor Nanorod and Nanoplatelet Heterostructures with Polarized Emission for Liquid Crystal Display Technology

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Autor(es):
Cunningham, Patrick D. [1, 2] ; Souza, Jr., Joao B. [1, 2, 3] ; Fedin, Igor [1, 2] ; She, Chunxing [1, 2] ; Lee, Byeongdu [4] ; Talapin, Dmitri V. [1, 2, 5]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Chicago, Dept Chem, 5735 S Ellis Ave, Chicago, IL 60637 - USA
[2] Univ Chicago, James Franck Inst, 5640 S Ellis Ave, Chicago, IL 60637 - USA
[3] Univ Sao Paulo, Inst Quim Sao Carlos, Colloidal Mat Grp, CP 780, BR-13566590 Sao Paulo - Brazil
[4] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 - USA
[5] Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 - USA
Número total de Afiliações: 5
Tipo de documento: Artigo Científico
Fonte: ACS NANO; v. 10, n. 6, p. 5769-5781, JUN 2016.
Citações Web of Science: 65
Resumo

Semiconductor nanorods can emit linear-polarized light at efficiencies over 80%. Polarization of light in these systems, confirmed through single-rod spectroscopy, can be explained on the basis of the anisotropy of the transition dipole moment and dielectric confinement effects. Here we report emission polarization in macroscopic semiconductor polymer composite films containing CdSe/CdS nanorods and colloidal CdSe nanoplatelets. Anisotropic nanocrystals dispersed in polymer films of poly butyl-co-isobutyl methacrylate (PBiBMA) can be stretched mechanically in order to obtain unidirectionally aligned arrays. A high degree of alignment, corresponding to an orientation factor of 0.87, was achieved and large areas demonstrated polarized emission, with the contrast ratio I-parallel to/I-perpendicular to= 5.6, making these films viable candidates for use in liquid crystal display (LCD) devices. To some surprise, we observed significant optical anisotropy and emission polarization for 2D CdSe nanoplatelets with the electronic structure of quantum wells. The aligned nanorod arrays serve as optical funnels, absorbing unpolarized light and re-emitting light from deep-green to red with quantum efficiencies over 90% and high degree of linear polarization. Our results conclusively demonstrate the benefits of anisotropic nanostructures for LCD backlighting. The polymer films with aligned CdSe/CdS dot-in-rod and rod-in-rod nanostructures show more than 2-fold enhancement of brightness compared to the emitter layers with randomly oriented nanostructures. This effect can be explained as the combination of linearly polarized luminescence and directional emission from individual nanostructures. (AU)

Processo FAPESP: 14/10736-7 - Síntese de pontos quânticos de CdSe recobertos com nanobastões de CDs em nanoestruturas do tipo caroço-casca
Beneficiário:João Batista Souza Junior
Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado