Electroluminescent devices visible spectrum

Figure 11.27 PL spectrum (- -) for Sm(DBM)3(Bath) film by excitation at 448 nm and EL spectrum (-) for the device driven by 4.5 V in the NIR region [73]. (Reproduced from B. Chu et al., Observation of near infrared and enhanced visible emissions from electroluminescent devices with organo samarium(III) complex, Journal of Physics D Applied Physics, 39, 4549-4552, 2006, with permission from Institute of Physics and lOP Publishing Limited.)...

Another potential application for LEDs is in illumination. The requirements for devices that serve as illumination sources are somewhat different than the monochromatic OLEDs described above. OLEDs targeted for RGB displays have to give electroluminescent spectra with a relatively narrow line shape centered on the peak wavelength. On the other hand, an illumination source is meant to approximate the blackbody solar spectrum and needs to have a broad line shape with roughly equal intensity across the entire visible spectrum. Therefore, in order to attain complete coverage across the visible spectrum, an OLED used for illumination purposes typically employs multiple emitters are that are either co-deposited into a single emissive layer or distributed into different layers or regions of the device. A number of the different device architectures have been reported to achieve efficient white EL and are discussed below. 

Anikeeva PO, Halpert JE, Bawendi MG, Bulovic V (2009) (Juantum dot hght-emitdng devices with electroluminescence tunable ovta the entire visible spectrum. Nano Lett 9 2532... 

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