PLEDs diodes

As a class of n-type organic semiconductors, PBI derivatives have received considerable attention for a variety of applications [312, 313], for example, for organic or polymer light-emitting diodes (OLEDs and PLEDs) [314, 315], thin-film organic field-effect transistors (OFETs) [316, 317], solar cells [318, 319], and liquid crystals [320]. They are also interesting candidates for single-molecule device applications, such as sensors [321], molecular wires [322], or transistors [141]. 

PL and EL emissions from a very low band-gap copolymer 330 (Eg 1.27eV) was demonstrated by Swedish researchers [411]. The material has two absorption peaks at 400 and 780 nm and emits light in the NIR region. The PL spectrum of thin films has one peak at 1035 nm, which is blue-shifted by ca. 60 nm on annealing at 200°C for 10min. The ITO/PEDOT/330/Ca/Al diode was positively biased when the Al/Ca electrode was connected to lower potential and the EL emission became observable at 1.1 V (AEL = 970 nm). The d>KLfor a nonoptimized device was quite low (0.03-0.05%), nevertheless demonstration of EL from PLED in the NIR can be important for communication and sensor technologies (Chart 2.85). 

EL with 4>el = 0.05% was observed in multilayer LB-film PLED ITO/399/A1, with a ratio in EL between the parallel and perpendicular orientations of 1.3 [523]. An even higher ratio of 2.4 was achieved in ITO/422/Ca/Al diode made from a stretch-oriented polymer film [524]. For more information on polarized LEDs, see Chapter 5 in this book. 

Excellent electron-transporting properties of quinoxaline (also demonstrated for noncon-jugated quinoxaline-containing polymer 588 [684] and quinoxaline-based polyether 589 [685]) resulted in a substantially decreased turn-on voltage of PPV/590 PLED (3.6 V), which is much lower than that of pure PPV in the same conditions (7 V). These diodes showed a maximum luminance of 710 cd/m2 (ca. 40 times brighter than the PPV diode at the same current density and voltage) [686]. 

R.E. Martin, F. Geneste, and A.B. Holmes, Synthesis of conjugated polymers for application in light-emitting diodes (PLEDs), C.R. Acad. Sci. Paris, t. 1, Serie IY 447 -70, 2000. 

FIGURE 9.6 Top and cross-section views of the fabricated 4-a-Si H TFTs pixel electrode circuits are shown. This pixel electrode circuit was used in 100 dpi AM-PLED. (From Flong, Y., Nahm, J.-Y., and Kanicki, J., IEEE J. Selected Top. Quantum Electron. Org. Light-Emitting Diodes, 10, 1, 2004. With permission.)... 

The impedance of PLEDs can be viewed in many different formats G-B, R-X, or as a function of frequency (see Figure 10.6). The diode in this example was ITO/PEDOT PSS/Alkoxy-PPV/Ca/Al, measured from 102 to 107Hz, with forward bias from 0 to 5 V. 

American Chemical Society), 77 403 Polymer-only treatment, in industrial water treatment, 26 133 Polymer organic light-emitting diodes (PLEDs), 7 540... 

Polymers Enable New Display Technologies with PLEDs (Polymer Light Emitting Diodes)... 

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