Light conjugated polymers

Interface control of light-emitted devices based on pyridine-containing conjugated polymers 99ACR217. 

One idea to realize a pin junction with conjugated polymers is to create it in situ by electrochemical doping. By using the conjugated polymer in a solid slate electrochemical cell, the production of bipolar light-emitting pin junction devices can be realized [69, 70]. 

The enormous progress in the field of electroluminescent conjugated polymers has led to performances of oiganic light-emitting devices (LEDs) that are comparable and in some aspects superior to their inorganic counterparts 11). Quantum efficiencies in excess of 5% have been demonstrated [2] and show that a high fraction of the injected carriers in a polymeric electroluminescence (EL) device form electronic excitations which recombine radiatively. 

Figure 15-29. Chemical structures of the conjugated polymers used in the device and the device structure of the laminated solar cell. For the top half of the device, A1 or Ca was evaporated on glass substrates, and the acceptor material MEH-CN-PPV (and a small amount of POPT, usually 5%) was spin coaled. The half with the POPT (and a small amount of MEH-CN-PPV, usually 5%) was spin coaled on 1TO substrates and heated to 200"C under vacuum belore the device was laminated together by applying a light pressure.

In all our conjugated polymer samples R is less than 0.1 and AR/R< I0-6 [7J. Because AT/T is typically in the range of I0-1I0 5, the second term in (3) can be neglected. This relation holds only in the small signal limit (A thin films, where the pump light is absorbed uniformly, creating an equal distribution of Aa across the film. 

Light-emitting diodes (LEDs) based on the electroluminescent conjugated polymers (Fig. 47) have attracted significant attention, both in academic research and industrial development, and are now on the edge of commercialization (Burroughs et al. 1990, Barth and Bassler 1997). Polymer LEDs require properties such as shown in Table 11. Recently, ef-... 

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