Emission-color design

These observations inspired Inganas and coworkers [107,497,498] to exploit the principle of steric hindrance to design PTs with emission colors spanning the full visible spectrum. A wide range of 3-substituted and 3,4-disubstituted thiophenes has been synthesized and successfully polymerized by FeCl3 in chloroform, affording polymers 411-424 [466, 498-501] (Chart 2.100). 

The Worldwide Phosphor Type Designation System (WTDS) the optical data of the specifies phosphors for cathode-ray tubes [5.429]. It replaces several phosphor designation systems (e.g., TEPAC, Pro Electron) previously in use in various countries. The phosphors are characterized by two capital letters, the first giving the position of the emission color in the Kelly Charts of Color Designation ... 

When designing light-emitting materials for OLEDs, three main issues must be addressed emission color, emission efficiency, and lifetime. Although OLED studies have demonstrated... 

In terms of polymer design, side groups have been added to PPV to make it solution-processable and to time the emission color. Additionally, the class of polymers utilized in PLEDs has expanded beyond substituted p-phenylenevinylenes to include homopolymers and copolymers of p-phenylenes [8-10], 2,7-fluorenes [11,12], and 2,5-thienylenes [13,14] (see Chart 5.1 for structures of polymers and abbreviations used through out this text). A quick review of the literature reveals that there has been a plethora of research on polymers for use as active layers in PLEDs. It is now possible to tune the emission of the polymer from blue to green to red, to engineer the HOMO and LUMO levels and, to vary the architecture of the chain from linear to dendritic. 

Two microfacet QWs that emitted different colors were designed. One emitted 500 nm from the (0001) facet and 400 nm from the 1122 facet (sample A), whereas the other emitted 580 nm from the (0001) facet and 430 nm from the 1122 facet (sample B). The In composition in the 1120 facet was insufficient to emit visible hght. Hence, the contribution from this facet was ignored. The emission color from each facet of the fabricated microfacet QWs was microscopically confirmed by CL at RT and was consistent with the design. 

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