A review was presented to demonstrate a historical description of the synthesis of light-emitting conjugated polymers for applications in electroluminescent devices. Electroluminescence (EL) was first reported in poly(para-phenylene vinylene) (PPV) in 1990 and researchers continued to make significant efforts to develop conjugated materials as the active units in light-emitting devices (LED) to be used in display applications. Conjugated oligomers were used as luminescent materials and as models for conjugated polymers in the review. Oligomers were used to demonstrate a structure and property relationship to determine a key polymer property or to demonstrate a technique that was to be applied to polymers. The review focused on demonstrating the way polymer structures were made and the way their properties were controlled by intelligent and rational and synthetic design.

Synthesis of Light-Emitting Conjugated Polymers for Applications in Electroluminescent Devices

Design of luminescent lanthanide complexes: From molecules to highly efficient photo-emitting materials

Organic-inorganic hybrid materials enable the integration of useful organic and inorganic characteristics within a single molecular-scale composite. Unique electronic and optical properties have been observed, and many others can be envisioned for this promising class of materials. In this paper, we review the crystal structures and physical properties of one family of crystalline, self-assembling, organic-inorganic hybrids based on the layered perovskite framework. In addition to exhibiting a number of potentially useful properties, the hybrids can be deposited as thin films using simple and inexpensive techniques, such as spin coating or single- source thermal ablation. The relatively new field of "organic-inorganic electronics" offers a variety of exciting technological opportunities. Several recent demonstrations of electronic and optical devices based on organic-inorganic perovskites are presented as examples.

Organic-inorganic electronics

Poly(1,6-heptadiyne)-Based Materials by Metathesis Polymerization.

Dye-doped nanoparticles for bioanalysis

The thermally stable second-order nonlinear optic (NLO) hybrid materials were successfully prepared by a sol−gel process using dye-attached sol−gel monomers (ormosils) of difunctionalized or trifunctionalized second-order NLO chromophores attached to silicon atoms. The dye-attached sol−gel monomers were synthesized by the coupling reaction of 3-isocyanatopropyltriethoxysilane with the corresponding functionalized NLO chromophores in DMAc. The dye-attached sol−gel monomers were homopolymerized and copolymerized with TEOS by hydrolysis and polycondensation in the presence of a slight excess amount of acidified water (pH 3), yielding the hybrid precusors (or a homogeneous solution). The hybrid precursors were spin-coated on various substrates such as ITO glass and NaCl disk. Hybrid films were further polycondensed by curing at 170 °C for 3 h. The cured hybrid materials existed in monohydroxy (T2, Q3) and nonhydroxy (T3, Q4) states, indicating the formation of a highly cross-linked silicon−oxygen polymeric ne...

Highly Efficient Organic/Inorganic Hybrid Nonlinear Optic Materials via Sol−Gel Process: Synthesis, Optical Properties, and Photobleaching for Channel Waveguides

Side-chain liquid-crystalline poly (1,6-heptadiyne)s and other side-chain liquid-crystalline polyacetylenes

Novel types of multifunctional polymer that contain a conjugated backbone for both third- and second-order nonlinear optical (NLO) materials have been investigated. We synthesized the 1,6-heptadiyne derivatives bearing NLO chromophores. The resulting monomers were easily homopolymerized and also copolymerized with ethyl dipropargyl(diethoxyphosphoryl)acetate (TDPA) using a metathesis catalyst to give corresponding polymers with large optical nonlinearities. Molecular structural characterizations for the resulting polymers were achieved by 1 H- and 13 C-NMR, FTIR, and UV-visible spectroscopies. The polymers obtained were found to be amorphous and showed thermal stability up to 250 °C. The homogeneous polymer solutions could be spin coated to the optical quality thin films on the ITO glass substrates. These films have been oriented by an electric contact poling process. The electro-optic coefficients, r 33 , of the poled polymer films were in the range 1.7-10.1 pm/v, and the nonresonant values of the third-order NLO coefficient, X (3) , were found to be (2.1-3.3) x 10 -11 esu.

Synthesis and Characterization of Novel Side-Chain Nonlinear Optical Polymers Based on Poly(1,6-heptadiyne) Derivatives

Novel side chain NLO organic/inorganic polymers were developed by sol-gel process of dye-contained triethoxysilane with tetraethoxysilane. A NLO moiety based on 4-[N, N-bis(2-hydroxyethyl)amino]-4′-nitrostilbene (diol-DANS) was covalently bounded to the triethoxysilane derivative. The sol-gel derived NLO polymers were analyzed by analytic techniques, including FT-IR, TGA, solid state 29Si-NMR, SEM, etc. The incorporation of the DANS dye into silicon oxide networks induces high dimensional stability of dipole alignment and the easy film fabrication. They exhibited a significant improvement in the thermal stability at high temperatures exceeding 270°C. The electro-optic coefficient at 1.3 μm is 4.3 pm/V for the copolymer containing 50 wt % of the dye-contained triethoxysilane system poled with corona discharge and is shown excellent long-term stability with 80% of initial value even after 3 hrs at 150°C.

Synthesis and optical-properties of novel side-chain nlo organic-inorganic polymers via sol-gel process

A new type of processable electroluminescent polymer containing tertiary amine linkage was prepared by typical Wittig reaction between bis(4-formylphenyl) n-butylamine and diphosphonium salt. The resulting polymer was highly soluble in common organic solvents so that it could be spun-cast onto glass plate coated with ITO electrode to give highly transparent homogeneous thin film. The molecular weight of the polymer determined by gel permeation chromatography using polystyrene standards is Mn = 4,500, Mw = 11,600. The structure of the polymer was confirmed by IR, UV-visible, and 1H-and 13C-NMR spectroscopy. We observed successfully the electroluminescence peaked at around 530 nm from the device made of the synthesized polymer. The current-voltage (I-V) curves showed typical rectifying diode characteristic.

Su-Jin Kang

Papers

Highly Efficient Organic/Inorganic Hybrid Nonlinear Optic Materials via Sol−Gel Process: Synthesis, Optical Properties, and Photobleaching for Channel Waveguides

Side-chain liquid-crystalline poly (1,6-heptadiyne)s and other side-chain liquid-crystalline polyacetylenes

Synthesis and Characterization of Novel Side-Chain Nonlinear Optical Polymers Based on Poly(1,6-heptadiyne) Derivatives

Synthesis and optical-properties of novel side-chain nlo organic-inorganic polymers via sol-gel process

Synthesis and Characterization of Novel Amine-Contained Electroluminescent Polymer