Organic electroluminescence quantum

Poly[2,5-dialkoxy-l,4-phenylene) vinylenejs with long solubilizing alkoxy chains dissolve in conventional organic solvents such as chloroform, toluene, or tetrahydrofuran [21, 28, 32-36]. Their emission and absorption spectra are red-shifted relative to PPV itself, and the polymers fluorescence and electroluminescence quantum yields are greater than parent PPV. This benefit may be a consequence of the long alkyl chains isolating the polymer chains from each other. 

Park, J.W., Ullah, M. H., Park S.S. and Ha, C.S. (2007). Organic electroluminescent devices using quantum-size silver nanoparticles. J Mater Sci Mater. Electron. 18 S393-S397... 

Okamoto. S. Tanaka. K. Izumi. Y. Adachi. H. Yamaji. T. Suzuki. T. (2001). Simple Measurement of Quantum Efficiency in Organic Electroluminescent Devices. Japanese Journal of Applied Physics, vol. 40, no. 7B, L783-4. 

We believe that there are two basic reasons for this situation. Eirstly, the Marcus theory has only been experimentally validated since the beginning of the 1980s. Secondly, the advent of organic material science and, in particular, the development of Organic Electroluminescent Diodes (OLED s) has given significant impetus to the development of quantum chemical calculations related to electron and energy transfer in and between molecules. 

The photoluminescence of polyaniline has been studied as a function of the polymer redox state. It was stated that each of the three PANI species have fluorescent emissions with different quantum yields. When conductive domains are present, the emission fi-om excitons located either inside these domains or near to them is efficiently quenched [40], Organic electroluminescent devices (LED s) are a possible alternative to liquid crystal displays and cathodic tubes, especially for the development of large displays. The principal setup for a polymeric LED is ITO/light-emitting polymer/metal. A thin ITO electrode on a transparent glass or polymeric substrate serves as the anode, while metals such as Al, Ca or Mg are used as cathode materials. After applying an electric field, electrons and holes are injected into the polymer. The formation of e /h" " pairs leads to the emission of photons. One of most important opportunities to follow from the use of poly-... 

Ohmori, Y., Fujii, A, Uchida, M., Morishima, C., and Yoshino, K., Fabrication and characteristics of 8-hydroxyquinoline aluminum/aromatic diamine organic multiple quantum well and its use for electroluminescent diode, Appl. Phys. Lett., 62, 3250-3252 (1993). 

Ishii H, Sugiyama K, Yoshimura D, Ito E, Ouehi Y, Seki K (1998) Energy-level alignment at model interfaces of organic electroluminescent devices smdied by UV photoemission Trend in the deviation from the traditional way of estimating the interfacial electronic structures. IEEE J Selected Topics in Quantum Chemistry 4 24—33... 

Electroluminescent Device Using PbBr-Based Layered Perovskite Having Self-Organized Organic-Inorganic Quantum-Well Structure... 

In electroluminescent applications, electrons and holes are injected from opposite electrodes into the conjugated polymers to form excitons. Due to the spin symmetry, only the antisymmetric excitons known as singlets could induce fluorescent emission. The spin-symmetric excitons known as triplets could not decay radiatively to the ground state in most organic molecules [65], Spin statistics predicts that the maximum internal quantum efficiency for EL cannot exceed 25% of the PL efficiency, since the ratio of triplets to singlets is 3 1. This was confirmed by the performance data obtained from OLEDs made with fluorescent organic... 

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