Luminescence phosphorescence devices

Keywords Luminescence m Fluorescence m Phosphorescence a Sensors a Switches a Logic Gates a Supramolecular Systems a Truth Tables a Photoinduced Electron Transfer a Molecular-Level Devices... 

In their follow-up paper, they also demonstrated 100% efficient energy transfer of both singlet and triplet excited states. The device exhibits peak external efficiency and power efficiency of 25 cd/A and 17 lm/W at 0.01 mA/cm2, respectively [343]. Liu demonstrated a high-efficiency red OLED employing DCJTB as a fluorescent dye doped in TPBI with a green phosphorescent Ir(ppy)3 as a sensitizer. A maximum brightness and luminescent efficiency of... 

A complementary application to the use of Os complexes in photovoltaic cells is the use of luminescent Os complexes in electroluminescent devices. There has been a significant amount of work in this area, particularly as it applies to the development of Os complexes with high quantum yields for phosphorescence. A review of transition metal complexes used in OLED development was published in 2006 by Evans et al. [126]. Another very recent review discusses various Os(II) carbonyl complexes with diketonate, hydroxyquinolate, bipyridine, and phenanthroline ligands as emitters in OLED devices [127]. A few select examples of Os complexes in OLEDs are presented here. 

Some degree of temporal resolution of emission may be obtained by incorporating a phosphoroscope attachment in the simple apparatus described above. A mechanical or electronic device is used to allow periodic and out-of-phase excitation and detection of luminescence. In the simplest case a mechanical shutter interrupts the excitation beam periodically and the detection system is gated so that emission is observed only after a fixed interval of time has elapsed after excitation. Under these conditions short-lived processes such as prompt fluorescence will have decayed to zero intensity and only longer-lived emission will be recorded. For mechanical devices the limit of measurable lifetime is of the order of 1 ms, thus allowing time resolved studies to be made of certain phosphorescence and delayed emission procesres (see ... 

An implicit reason that these phenomena are usable in electric and electro-optical devices is the brief interval during which these luminescent processes occur, as electronics require such rapid reactions for high operating frequencies to ensure, for example, constant communication and screen updating. Most fluorescent and phosphorescent processes occur on a time scale of ns to ps or ms to /xs, respectively. 

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