Triplet exciton interactions in solid films of an electrophosphorescent Pt (II) porphyrin

M&ecedil;żyk, J.; Kalinowski, J.; Meinardi, F.; Tubino, R.
March 2005
Applied Physics Letters;3/14/2005, Vol. 86 Issue 11, p111916
Academic Journal
We demonstrate the phosphorescence (PH) from neat Pt (II) porphyrin (PtOEP) films to be quenched by bimolecular reactions of monomeric (M) and dimeric (D) triplet (T) excitons. Their respective rate constants, γTT(M)≅8×10-12 cm3/s and γTT(D)≅8×10-15 cm3/s, were found from the kinetics fits to the excitation intensity dependence of the relative PH yield. The exciton decay becomes dominated by mutual annihilation above a critical concentrations of TMcrit≅6.3×1017 cm-3 for M, and TDcrit≅1.2×1019 cm-3 for D triplet excited states. These data allow us to exclude T–T annihilation as the nonradiative pathway quenching the emission from guest aggregates in PtOEP-doped emitters, and predict the onset of the current roll-off in electrophosphorescence efficiency at a current that exceeds four orders of magnitude the values observed experimentally with light-emitting-diodes based on thin PtOEP-doped emitting layers.


Related Articles

  • Predicting plant sulfur deficiency in soils: results from Ohio. David Kost; Liming Chen; Warren Dick // Biology & Fertility of Soils;Sep2008, Vol. 44 Issue 8, p1091 

    Abstract  We developed a model for plant available sulfur (S) in Ohio soils to predict potential crop plant S deficiency. The model includes inputs of plant available S due to atmospheric deposition and mineralization of soil organic S and output due to leaching. A leaching index was...

  • Making a single-chain four-helix bundle for redox chemistry studies. Kristina Westerlund; Sean D. Moran; Heidi K. Privett; Sam Hay; Jüri Jarvet; Brian R. Gibney; Cecilia Tommos // PEDS: Protein Engineering, Design & Selection;Nov2008, Vol. 21 Issue 11, p645 

    The construction and characteristics of the stable and well-structured α4W protein are described. The 117-residue, single-chain protein has a molecular weight of 13.1 kDa and is designed to fold into a four-helix bundle. Experimental characterization of the expressed and purified protein...

  • Effect of pH on survival, reproduction, egg viability and growth rate of five closely related rotifer species. Xu Yin; Cui Niu // Aquatic Ecology;Dec2008, Vol. 42 Issue 4, p607 

    Abstract  In the laboratory we examined the effect of pH (5–10 with one interval) on survival, reproduction, egg viability and growth rate (intrinsic growth rate—r m and population growth rate—r) of five Brachionus rotifer species (B. calyciflorus,...

  • Changes in the quality indices during ice storage of farmed Senegalese sole ( Solea senegalensis ). Margarita Tejada; Cristina De las Heras; Michael Kent // European Food Research & Technology;Jun2007, Vol. 225 Issue 2, p225 

    Abstract  Farmed Senegalese sole (Solea senegalensis) from two different cultivation areas in Spain and different rearing conditions were analyzed up to 28 days in order to establish changes in the quality indices during ice storage and select the best ones to be used to...

  • Oxidases from mate tea leaves ( Ilex paraguariensis ): extraction optimization and stability at low and high temperatures. Eliana Baldissera; Octávio Antunes; J. Vladimir Oliveira; Cláudio Dariva; Débora de Oliveira // Bioprocess & Biosystems Engineering;Oct2008, Vol. 31 Issue 6, p541 

    Abstract  Mate (Ilex paraguariensis) is an important natural product in the economic and cultural context of Brazil. Peroxidase and polyphenol oxidase have been responsible for quality deterioration and browning in mate. The objective of this work was to investigate a methodology...

  • Characterization of Thermo-stable Endoinulinase from a New Strain Bacillus Smithii T7. Wei Gao; Yongming Bao; Yang Liu; Xiuli Zhang; Jingyun Wang; Lijia An // Applied Biochemistry & Biotechnology;Jun2009, Vol. 157 Issue 3, p498 

    Abstract  A new thermophilic inulinase-producing strain, which grows optimally at 60 °C, was isolated from soil samples with medium containing inulin as a sole carbon source. It was identified as a Bacillus smithii by analysis of 16s rDNA. Maximum inulinase yield of 135.2 IU/ml...

  • Mechanisms of Enamel Dissolution in Acid Buffers. HIGUCHI, WILLIAM I.; GRA Y, JOHN A.; HEFFERREN, JOHN J.; PATEL, PRAFULL R. // Journal of Dental Research;Mar1965, Vol. 44 Issue 2, p330 

    The article presents a study which examines the mechanisms of dental enamel dissolution in acid buffers. An equation used to measure the rate of dissolution is reviewed, taking into count hydrogen-ion concentration and buffer-acid dissociation. The author focuses on the dissolution of...

  • Effect of mobile phase nature on the selectivity of separation of 5,7-dinitrobenzofurazan derivatives of amino compounds by reversed-phase HPLC. Evgen'ev, M.; Evgen'eva, I.; Valitova, Ya. // Journal of Analytical Chemistry;Aug2012, Vol. 67 Issue 8, p728 

    Selectivity coefficients of a series of 5,7-dinitrobenzofurazan derivatives of amino compounds in the separation by reversed-phase HPLC have been calculated. Influence of the character and concentration of organic modifier and pH of the buffer solution in the mobile phase on the selectivity of...

  • Reader Questions: Mobile Phase. Dolan, John W. // LC-GC North America;Jul2005, Vol. 23 Issue 7, p662 

    Sometimes the mobile phase conditions selected for reversed-phase and ion-pairing methods stein either arbitrary or mysterious The two examples discussed in this month's "LC Troubleshooting" have allowed us to dissect the mobile-phase characteristics to see their importance and contribution to...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics