Synthesis and Electrochemical Properties of Peripheral Carbazole Functional Ter(9,9-spirobifluorene)s

Dihydroindenofluorenes as building units in organic semiconductors for organic electronics

This review aims to discuss organic semiconductors constructed on dihydroindenofluorene positional isomers, which are key molecular scaffolds in organic electronics. Bridged oligophenylenes are key organic semiconductors that have allowed the development of organic electronic technologies. Dihydroindenofluorenes (DHIFs) belong to the family of bridged oligophenylenes constructed on a terphenyl backbone. They have proven to be very promising building blocks for the construction of highly efficient organic semiconductors for all OE devices, namely organic light emitting diodes (OLEDs), phosphorescent OLEDs, organic field-effect transistors (OFETs), solar cells, etc.

A novel structure of grid spirofluorene: a new organic semiconductor with low reorganization energy

The lower charge mobility of organic semiconductors relative to that of inorganic semiconductors is a thorny problem that still has not been resolved.

Theoretical design study on photophysical property on oligomers based on spirobifluorene and carbazole-triphenylamine for PLED applications

The photophysical properties of five blue light-emitting polymers based on spirobifluorene applied in polymer light-emitting diodes (PLED) materials have been studied by quantum chemistry. In order to understand the intrinsic reasons for the different performances displayed by the polymers, we carried out density functional theory (DFT) and Marcus theory investigations on their oligomers in terms of structure and properties stability, absorption and emission properties, and carrier injection and transport properties. Especially, some important parameters which had not been reported to our knowledge were given in this contribution, such as the ionization potentials (IPs), electron affinities (EAs), reorganization energies (λ), ke/kh (the ratio between the electron transfer rate (ke) and hole transfer rate (kh)), and the radiative lifetimes (τ). The main results indicate that the co-oligomers of PCC-1, PCC-2, and PCC-3 with push-pull interactions produced by the existing D-A segments have better carrier injection and transport properties than the oligomers of PSF and PCF. Especially PCC-2 co-oligomer, its large radiation lifetime (7.46 ns) and well balanced and adequate carrier transport guarantee its champion performance for PLED. The calculated results coincide with the experimental ones. Besides, PNF structurally similar to PCC-2 has similar photoelectric properties to PCC-2 in theory, and the fluorescence emission of PNF co-oligomer is superior to PCC-2 co-oligomer. Therefore, we predict that PNF is a promising candidate for PLED.

Synthesis of Dendritic Oligo-Spiro(fluorene-9,9'-xanthene) Derivatives with Carbazole and Fluorene Pendants and their Thermal, Optical, and Electroluminescent Properties

Two novel spiro-configured ter(arylene-ethynylene) derivatives, TSF-Cz and TSF-F, have been designed and synthesized using spiro(fluorene-9,9'-xanthene) (SFX) as building blocks, introducing a hole-transporting carbazole and a fluorene chromophore as the peripheral functional group into the backbone through an oxygen atom. The two well-defined oligomers possess good solubility, film-forming quality, and high T(g) 's at 140 and 126 °C, respectively. In addition, these oligomers exhibit blue photoluminescence (PL) emission both in solution and solid states. The double-layered devices fabricated using the two materials as the emitter show a sky-blue emission with a brightness and a current efficiency of 7 613 cd · m(-2) and 1.11 cd · A(-1) for TSF-Cz, and 1 507 cd · m(-2) and 0.36 cd · A(-1) for TSF-F, respectively.