Polyfluorenes layers

Zen A, Neher D, Bauer C, Asawapirom U, Scherf U, Hagen R, Kostromine S, Mahrt RF. 2002. Polarization sensitive photoconductivity in aligned polyfluorene layers. Appl Phys Lett 80 4699 4701. 

Rhenium(I) tricarbonyl-2,2 -bipyridine moieties were used to cap both ends of a poly fluorine, yielding Re-capped Re(bpy)(CO)3(py)-X-(py)(CO)3(bpy)Re 2+ polymers, where X = polyfluorene [51, 52], The polymers with and without the Re caps were spin-coated from their solutions in CH2C12 onto an ITO surface previously modified with a layer of poly(styrene sulfonic acid), doped with poly(ethylenedioxythiophene). The LED (light-emitting device) was then topped with a layer of Ca/Al. The photoluminescence (PL) and electroluminescence seen were consistent with the presence of [Re(bpy)(CO)3(py)]+ [158],... 

The first quantitative study of the device efficiency of polyfluorene LEDs was reported by Grice and co-workers in 1998.5 The LED used ITO-coated glass as the anode, a hole-transport layer of a polymeric triphenyldiamene (poly-TPD), an emissive layer of PFO, and a calcium cathode. A schematic energy-level structure for the device is inset in Fig. 10.14. The injection barrier for holes into poly-TPD is approximately 0.3 eV, much less than that for PFO (0.8 eV), and the injection barrier for electrons into PFO is approximately 0.1 eV. Poly-TPD had excellent film-forming properties, was transparent to PFO emission, and was insoluble in... 

Although polyfluorene has been a popular active layer material for OLEDs, it suffers from oxidative degradation characterized by the emergence of a green emission band. Poly(2,7-dibenzosilole), with its higher thermal stability and resistance to oxidation, is a potential alternative to polyfluorene [23]. OLEDs fabricated from poly(2,7-dibenzosilole), with a configuration of ITO/PEDOT PSS/polymer(65 nm)/Ba/Al, showed emission maxima... 

Persson N-K, Schubert M, Inganas O (2004) Optical modelling of a layered photovoltaic device with a polyfluorene derivative/fullerene as the active layer. Sol Energy Mater Sol Cells 83 169... 

PEDT PSS/emission-layer/Ba/Al devices with the red dye pic2Ir(acac) blended into either a PVK PBD(40 wt. %), a PFO PBD (30 wt. %) or a PFTA PBD (30 wt. %) host (where PFTA is a hyperbranched polyfluorene with a triphenyl-amine core). Even though the maximum efficiencies of all devices were quite comparable (10%), the voltage to drive the PFTA PBD device at ca. 1300 cd/m2 was only 10.1 V, compared to 13.9 V for the PVK PBD device. 

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