Polymer light-emitting diode emission layer

The photoconductivity of polysilanes was described in Section 5.8, and their electroluminescence is covered in Section 5.9.2. These properties make polysilanes possible components of polymer light-emitting diodes, either as charge transport layers or as the actual emissive materials.146 A drawback of the polysilanes is their photodegradation under ultraviolet irradiation, a problem which must be overcome if polysilanes are to become commercially useful. 

The electroluminescent performance of single-layer polymer light-emitting diodes with their emissive layer of PVK and electron transporting molecules of iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,C ]-picolinate has been investigated [84]. 

We fmd(8-12) that the performance of polymer light-emitting diodes (LEDs) having the configuration Al/MEH-PPV/ITO where MEH-PPV=poly(2-methoxy-5-(2 -ethyl-hexyloxy)-l,4-phenylene-vinylene) are drastically alter by light io ne doping of the emissive MEH-PPV layer. For nondoped Al/MEH-PPV/ITO devices,... 

Light emitting diodes (LEDs) have also been fabricated from conjugated polymers such as poly (p-phenylene-vinylene) as the emissive layer [40]. The advances in the chemistry of processible... 

By a proper selection of the monomers and their ratios in the polymerization, the emissive polymer can be synthesized. The film formed of the electroluminescent polymer or copol5mier can be used as a light emissive layer in a single layer polymeric light-emitting diode. 

Different two layer light emitting diodes (LEDs) have been tested using the aromatic oxadiazole polymers as electron transporting layer, with PPV as emissive layer. It was found that the use of the aromatic oxadiazole polymers can realise efficient light emission using stable aluminum metal as cathode. No definite enhancement of electroluminescence efficiency has yet been observed. This can probably be explained by the fact that PPV and the oxadiazole polymers 18-20 have similar reduction potentials, and therefore by analogy similar LLMO levels. 

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