Polymer light emitting electrodes

In the many reports on photoelectron spectroscopy, studies on the interface formation between PPVs and metals, focus mainly on the two most commonly used top electrode metals in polymer light emitting device structures, namely aluminum [55-62] and calcium [62-67]. Other metals studied include chromium [55, 68], gold [69], nickel [69], sodium [70, 71], and rubidium [72], For the cases of nickel, gold, and chromium deposited on top of the polymer surfaces, interactions with the polymers are reported [55, 68]. In the case of the interface between PPV on top of metallic chromium, however, no interaction with the polymer was detected [55]. The results concerning the interaction between chromium and PPV indicates two different effects, namely the polymer-on-metal versus the metal-on-polymer interface formation. Next, the PPV interface formation with aluminum and calcium will be discussed in more detail. 

C Zhang, S Hoger, K Pakbaz, F Wudl, and AJ Heeger, Improved efficiency in green polymer light-emitting diodes with air-stable electrodes, J. Electron. Mater., 23 453 458, 1994. 

A.R. Schlatmann, D.W. Floet, A. Hilberer, F. Garten, P.J.M. Smulders, T.M. Klapwijk, and G. Hadziioannou, Indium contamination from the indium tin-oxide electrode in polymer light-emitting diodes, Appl. Phys. Lett., 69 1764—1766, 1996. 

Deeper insight into CNT functionalities when used as a dopant for polymer solar cells and polymer light-emitting diodes (PLEDs) was presented by Xu et al. [329]. While the PLED gained from rather low CNT doping levels of about 0.02%, the solar cell performance increased further up to 0.2 wt %. The improved EQE of the OLED was explained by a better charge carrier injection from the electrode, whereas for the solar cell exciton dissociation is facilitated by the nanotubes [329]. 

Cao Y, Yu G, Parker ID, Heeger AJ (2000) Ultrathin layer alkaline earth metals as stable electron-injection electrodes for polymer light emitting diodes. J Appl Phys 88 3618... 

C.M. Ramsdale and N.C. Greenham. The optical constants of emitter and electrode materials in polymer light-emitting diodes. J. Phys. D., Appl. Phys., 36(4) L29— L34, 2002. 

Q, 2011c. Highly flexible silver nanowire electrodes for shape-memory polymer light-emitting diodes. Adv. Mater. 23, 664-668. Copyright 2011, Wiley-VCH. 

According to the similar method, a fiber-shaped polymer light-emitting diode (PLED) was developed on the PET fiber by adip-coatingmethod exceptfor the thermal-evaporation of the outermost Al semitransparent electrode. This PET-based fiber-shaped PLED showed a high luminance of over 1000 cd m which was high enough for application in wearable... 

Y. Yang and A. J. Heeger, Polyanihne bilayer composite electrode for efficient polymer light emitting diodes. Mol. Cryst. Liq. Cryst. 256, 537—542 (1994). 

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