Bipolar ac light-emitting devices

The single-layer devices, the bilayer devices (with and without the PAN-CSA network electrode), and the inverted devices discussed are unipolar devices operating under a single-bias condition. We now discuss two novel device configurations that can be operated in both forward and reverse dc biases as well as in ac modes the SCALE devices and color-variable bipolar/ac light-emitting devices. 

For the devices presented here, the wrapped copolymer PPyVPV and a wrapped copolymer of poly thiophene and polyphenylene derivative, PTP, were used as the emitting materials SPAN and EB were used as the redox materials ITO and Al were used as electrodes. Figure 9.11 shows the schematic diagram of the device structure of the color-variable bipolar/ac light-emitting devices. 

Wang, Y.Z., D.D. Gebler, D.K. Fu, T.M. Swager, and A.J. Epstein. 1997. Color variable bipolar/ac light-emitting devices based on conjugated polymers. Appl Phys Lett 70 3212-3217. 

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