Homeotropic Alignment Of A Columnar Liquid Crystal With Multiwalled Carbon Nanotubes

Todos os Trabalhos

Trabalho

Título do Trabalho

HOMEOTROPIC ALIGNMENT OF A COLUMNAR LIQUID CRYSTAL WITH MULTIWALLED CARBON NANOTUBES

Autores

Carlos Henrique Stadtlober (DR); UFSC
J. E. S. Olegário (IC); UFSC
Daniela Zambelli Mezalira
H. Bock (Pq); CRPP
L. G. França (PD); University of Durham
A. P. Monkman (Pq); University of Durham
Juliana Eccher

Modalidade

Apresentação - pôster (Clique aqui para saber os detalhes para submissão)

Área temática

Dispositivos eletrônicos e ópticos (OLED/OFET/OPVs/etc)

Data de Publicação

20/05/2022

País da Publicação

Brasil

Idioma da Publicação

Inglês

Página do Trabalho

https://www.even3.com.br/anais/workshopineo2022/473938-homeotropic-alignment-of-a-columnar-liquid-crystal-with-multiwalled-carbon-nanotubes

ISBN

Palavras-Chave

Liquid Crystals, Carbon Nanotubes, Homeotropic Alignment, Organic Electronics.

Resumo

Different types of organic charge-transport materials have been intensively studied for applications in organic electronic devices. As an interesting alternative, liquid crystals (LCs) have attracted attention in the past few years. The main advantage of LCs is related to the possibility of molecular alignment, which can be achieved with application of external stimulus, such as temperature and electric or magnetic fields. Among many types of LCs, columnar liquid crystals (ColLC) stand out as a promising material due to almost one-dimensional charge transport along the columns, which makes the homeotropic alignment ideal for organic solar cells (OSCs) and organic light emitting diodes (OLEDs) applications. Furthermore, to assist the charge transport in optoelectronic devices, carbon nanotubes (CNTs) are being used. The main reason is due to their mechanical stability and high charge carrier mobility, which allows their use as hole transport layers, exciton dissociation centers and transparent and flexible thin films to replace indium tin oxide (ITO) electrodes. Although the mechanical and electrical properties of CNTs, the dispersion stability has become a challenge due to its aspect ratio. To reach higher and stable concentrations, the addition of surfactants and chemical functionalization processes can be performed. Another route to achieve stability is to use LCs as hosts, the aromatic cores allow the adsorption of the molecules on CNT walls, decreasing van der Walls interactions between nanotubes and preventing aggregation. In this work, we have homeotropically aligned a ColLC based on the aromatic benzoperylene diimide diester center in the presence of Multi-walled CNTs (MWCNTs) for the first time and characterized thin films and tetrahydrofuran-based solutions of the composite. The incorporation of the MWCNTs in the columnar LC matrix was evidenced by: (i) lower phase transition temperatures; (ii) lower intensity of X-ray diffractogram peaks and (iii) changes in liquid-crystalline texture observed by polarized optical microscope. The aligned samples showed higher emission intensities compared to pristine films, which was also verified by absolute quantum yields measurements. In stationary photoluminescence spectra, a quenching of the LC emission was observed with the addition of the nanotubes. Furthermore, time-dependent photoluminescence with an ultrafast camera was performed and showed the presence of delayed fluorescence associated to triple-triplet annihilation (TTA).

Título do Evento: Workshop INEO 2022
Título dos Anais do Evento: Anais do Workshop INEO 2022
Nome da Editora: Even3
Meio de Divulgação: Meio Digital

Como citar

UFSC, Carlos Henrique Stadtlober (DR); et al.. HOMEOTROPIC ALIGNMENT OF A COLUMNAR LIQUID CRYSTAL WITH MULTIWALLED CARBON NANOTUBES.. In: Anais do 16° Workshop do Instituto Nacional de Eletrônica Orgânica. Anais...São Carlos(SP) IFSC, 2022. Disponível em: https//www.even3.com.br/anais/workshopINEO2022/473938-HOMEOTROPIC-ALIGNMENT-OF-A-COLUMNAR-LIQUID-CRYSTAL-WITH-MULTIWALLED-CARBON-NANOTUBES. Acesso em: 26/12/2024