polyfluorene

Despite the similar sounding names, polyfluorene is unrelated to the element fluorine.

One polymer used in the emissive layer is polyfluorene.

Substitution at the nine position with various moieties has also been examined as a means to control the color emitted by polyfluorene.

The design of polyfluorene derivatives relies on the character and properties of their monomers.

Conjugated polymers, such as polyfluorene, can be designed and synthesized with different properties for a wide variety of applications.

Only a small amount of the co-monomer, approximately 5%, was needed to tune the emission of the polyfluorene from blue to yellow.

Other less well studied conductive polymers include polyindole, polypyrene, polycarbazole, polyazulene, polyazepine, polyfluorene, and polynaphthalene.

Fluorene, a principal repeat unit in polyfluorene derivatives, was isolated from coal tar and discovered by Marcellin Berthelot prior to 1883.

In addition to LCDs, polyfluorene can also be used to synthesize light emitting diodes (LEDs).

Typical polymers used in PLED displays include derivatives of poly(p-phenylene vinylene) and polyfluorene.

Thus, polyfluorene copolymers have also been used in polymer:polymer blend solar cells, where their electron accepting, electron conducting and light absorbing properties permit device performance.

Microscopic grooves are then generated in the polyamide layer and the liquid crystal in contact with the polyamide, the polyfluorene, can align in the rubbing direction.

Interest in polyfluorene derivatives has increased because of their high photoluminescence quantum efficiency, high thermal stability, and their facile color tunability, obtained by introducing low-band-gap co-monomers.

The color of the molecules can be designed through synthetic control over the electron donating or withdrawing character of the substituents on fluorene or the comonomers in polyfluorene.

Since polyfluorene homopolymers emit higher energy blue light, they can transfer energy via Förster resonance energy transfer (FRET) to lower energy emitters.

Researchers have attempted to eliminate excimer formation and enhance the efficiency of polyfluorenes by copolymerizing polyfluorene with anthracene and end-capping polyfluorenes with bulky groups which could sterically hinder excimer formation.

For instance by adding electronegative groups on the end of conjugated side chains, researchers lowered the HOMO of a polyfluorene copolymer to 5.30 eV and increased the voltage of a solar cell to 0.99 V.

Polyfluorene polymers (where carbon 7 of one unit is linked to carbon 2 of the next one, displacing two hydrogens) are electrically conductive and electroluminescent, and have been much investigated for use as a luminophore in organic light-emitting diodes.