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Abstract: A series of phosphine oxide-functionalized polyfluorene derivatives, PFH-PO-40-1 (P1), PFH-PO-20-1 (P2), PFH-PO-10-1 (P3), and PFH-PO-1-1 (P4), were prepared via a palladium-mediated Suzuki cross-coupling reaction. The structures and purities of all polymers were fully characterized by 1H and 13C NMR, UV-vis and photoluminescent spectroscopy, gel permeation chromatography, and TGA/DSC. Their emission features showed single broad peaks at about 445 nm in film, compared with those in dilute solutions, which might be caused by some degree of aggregation in the excited states of the backbones. The best electroluminescence (EL) performance of these polymers with configuration of ITO/PEDOT:PSS/Polymer/Alq3/LiF/Al was obtained from P1 (current efficiency was 4.2 Cd/A at 6V).

The Foucault and Fresnel modes of Lorentz microscopy, together with a quantitative magnetization mapping technique, summed image differential phase-contrast imaging, were used to study the magnetization reversal mechanism of the sense layer in spin-valve structures exhibiting the giant magnetoresistance effect. In addition to studies of sheet film, lithographically defined spin-valve elements were investigated. A current can be passed through the element during magnetizing so that the effect of the applied current on the giant magnetoresistance and magnetization reversal mechanism can be studied. Results are presented for a number of different spin-valve structures.

The article discloses a fault tolerant light panel that relates to the field of solid-state lighting panels, particularly those manufactured as an array of organic light-emitting devices (OLEDs). The cost, power requirements and material usage in lighting or display products are expected to be reduced by this panel. Also described is a modular approach to link small OLED panels created by such methods as roll-to-roll. It cites the use of a large area, roll-to-roll processed mounting surface to achieve low-cost electrical isolation.