9 Molecular Designs for Solid-State Luminescent Properties …
311
polymer-based examples to offer intense emission as a solid material including a
film are illustrated. By loading luminescent materials in the transparent polymer
or organic–inorganic hybrid matrices, intermolecular interaction and subsequently
ACQ can be suppressed. As a result, solid-state emission was able to be observed.
Additionally, it was found that some of the luminophores are capable of simultaneously exhibiting each emission band in diverse wavelength regions from the single
materials. As a consequence, multiple color emission is detectable. Several studies on
these mixture films are introduced mainly from our researches. Next, the recent topics
on the development of solid-state luminescent molecules are explained. In particular,
since the first report on the aggregation-induced emission (AIE)-active molecule
(Luo et al. 2001), which shows enhanced emission only in the condensed state, a
wide variety of solid-state luminescent materials have been produced mainly with
tetraphenylethene (Tang et al. 2015). Moreover, stimuli-responsive luminochromic
materials, which show emission color changes in response to external stimuli or
environment alteration, have been also obtained based on the AIE-active molecules.
Their useful characters as a functional optical material and prediction of the new
AIE-active dyes are described.
9.2 Mixture Materials
As mentioned in the introduction, ACQ is mainly induced through intermolecular interactions in the condensed state. Therefore, the simple and facile strategy
for suppressing ACQ is to mix luminescent dyes with transparent matrices. From
this standpoint, conventional polymers and organic–inorganic hybrids are a suitable scaffold for obtaining luminescent materials. Additionally, material properties, such as rigidity, elasticity, and thermal stability, are originated from the
type of matrices. Therefore, it is relatively easy to obtain desired multi-functional
luminescent materials based on dye-containing mixtures.
Organic–inorganic hybrids have attracted attention because multiple characteristics originating from both organic and inorganic components (Gon et al. 2017). In
particular, hybridization with inorganic components is recently recognized as one of
effective strategies for obtaining robust products without crucial changes of intrinsic
optical properties of the loaded molecules. Therefore, applications of the dye-doped
hybrids have been accomplished for creating advanced optical devices, such as lightemitting diodes and dye-lasers. By maintaining the isolation state of organic dyes
in the products, ACQ can be effectively suppressed. Therefore, during the material
preparation, it is critically important to maintain homogeneous dispersion of organic
dyes. However, due to the polarity mismatch between organic dyes and inorganic
components (and sometimes organic matrices), unexpected aggregation, followed by
ACQ, is often induced. Therefore, the suppression of aggregation between the dyes
at the molecular level should be essential to obtain desired materials.
White-light emissive hybrids have been manufactured by loading each RGB
light-emitting organoboron dye (1,3-diketonate BF 2 complex, boron dipyrromethene
311
polymer-based examples to offer intense emission as a solid material including a
film are illustrated. By loading luminescent materials in the transparent polymer
or organic–inorganic hybrid matrices, intermolecular interaction and subsequently
ACQ can be suppressed. As a result, solid-state emission was able to be observed.
Additionally, it was found that some of the luminophores are capable of simultaneously exhibiting each emission band in diverse wavelength regions from the single
materials. As a consequence, multiple color emission is detectable. Several studies on
these mixture films are introduced mainly from our researches. Next, the recent topics
on the development of solid-state luminescent molecules are explained. In particular,
since the first report on the aggregation-induced emission (AIE)-active molecule
(Luo et al. 2001), which shows enhanced emission only in the condensed state, a
wide variety of solid-state luminescent materials have been produced mainly with
tetraphenylethene (Tang et al. 2015). Moreover, stimuli-responsive luminochromic
materials, which show emission color changes in response to external stimuli or
environment alteration, have been also obtained based on the AIE-active molecules.
Their useful characters as a functional optical material and prediction of the new
AIE-active dyes are described.
9.2 Mixture Materials
As mentioned in the introduction, ACQ is mainly induced through intermolecular interactions in the condensed state. Therefore, the simple and facile strategy
for suppressing ACQ is to mix luminescent dyes with transparent matrices. From
this standpoint, conventional polymers and organic–inorganic hybrids are a suitable scaffold for obtaining luminescent materials. Additionally, material properties, such as rigidity, elasticity, and thermal stability, are originated from the
type of matrices. Therefore, it is relatively easy to obtain desired multi-functional
luminescent materials based on dye-containing mixtures.
Organic–inorganic hybrids have attracted attention because multiple characteristics originating from both organic and inorganic components (Gon et al. 2017). In
particular, hybridization with inorganic components is recently recognized as one of
effective strategies for obtaining robust products without crucial changes of intrinsic
optical properties of the loaded molecules. Therefore, applications of the dye-doped
hybrids have been accomplished for creating advanced optical devices, such as lightemitting diodes and dye-lasers. By maintaining the isolation state of organic dyes
in the products, ACQ can be effectively suppressed. Therefore, during the material
preparation, it is critically important to maintain homogeneous dispersion of organic
dyes. However, due to the polarity mismatch between organic dyes and inorganic
components (and sometimes organic matrices), unexpected aggregation, followed by
ACQ, is often induced. Therefore, the suppression of aggregation between the dyes
at the molecular level should be essential to obtain desired materials.
White-light emissive hybrids have been manufactured by loading each RGB
light-emitting organoboron dye (1,3-diketonate BF 2 complex, boron dipyrromethene