Phosphorescent light

B In chemiluminescence light is emitted as the result of molecules being excited during a chemical reaction. In phosphorescence light is emitted when molecules remain excited after the stimulus has ceased. 

C Lee, KB Lee, and J Kim, Polymer phosphorescent light-emitting devices doped with tris (2-phenylpyridine) iridium as a triplet emitter, Appl. Phys. Lett., 77 2280-2282, 2000. 

FC Chen, Y Yang, and Q Pei, Phosphorescent light-emitting electrochemical cell, Appl. Phys. Lett., 81 4278-4280, 2002. 

EB Namdas, TD Anthopoulos, IDW Samuel, MJ Frampton, SC Lo, and PL Burn, Simple color tuning of phosphorescent light-emitting diodes, Appl. Phys. Lett., 86 161104-161106, 2005. 

Phosphorescence is observed when the dry sheet is dipped in a container with liquid nitrogen and illuminated by a UV lamp. Purine derivatives phosphoresce light blue pyrimidines are not visible. 

Opening of the chamber door and inspection of the inner areas using a UV lamp. Riboflavin residuals show up under phosphorescent light. The cleaning process can be considered successful if no phosphorescent visible residuals can be detected. 

Due to the large band gap and high triplet energy level of the poly(3, 6-dibenzosilole) 5, the copolymer is an excellent host for the fabrication of blue polymer phosphorescent light-emitting diodes. A high external quantum efficiency (t/el) of 4.8% and a luminance efficiency of 7.2 cd/A at 644 cd/m2 have been achieved for blue phosphorescence devices (emission peak (AEL) at 462 nm, CIE coordinates x = 0.15,y = 0.26). The performances of the devices are much better than those reported for blue phosphorescent devices with poly(A--viny 1 cabarzo 1 e) (PVK) as the host.32... 

A phosphorescent light is observed on heating ozonised oxygen to 350° C. A more powerful phosphorescence results on decomposing the vapour of liquid ozone with a hot glass rod.3... 

This has important consequences concerning the spatial resolution of the detector system. Due to scattering and total reflection at the edges of the polycrystalline particles, more phosphorescent light is lost in a thick layer than in a thinner one. In addition, the visible photons are more spread-out laterally in thicker screens. 

Figure 4.4 Jablonski-type energy diagrams for possible excited energy states when light interacts with matter, (a) Three possible transition pathways for return to ground state without radiation, (b) Two possible transition pathways with fluorescent light emission as final step on return to ground state, (c) Two possible transition pathways with phosphorescent light emission as final step on return to ground state.

Reineke, S., Walzer, K., and Leo, K. 2007. Triplet-exciton quenching in organic phosphorescent light-emitting diodes with Ir-based emitters. Phys. Rev. B 75 125328. 

Chan KL, Watkins SE, Mak CSK, McKieman Ml, Towns CR, Pascu SI, Holmes AB (2005) Poly(9,9-diaIkyl-3,6-dibenzosilole) a high energy gap host for phosphorescent light emitting devices. Chem Common 5766-5768... 

The absorption of the solar radiation at wavelengths longer than 219 run forms the excited SO2 molecules following the reaction (4.64), and photo-emission is observed in laboratory studies. The radiative lifetime of the excited state reached by the absorption of photons at 340-400 mn is rather long, 8.1 2.5 ms (Su et al. 1977), which is thought to correspond to phosphorescence (light-emission between the... 

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