The quantum yield of photoionization of TrpH and IndH from the nonrelaxed prefluorescent state S* increases with the temperature decrease. This effect is attributed to the competition between temperature independent ionization and ultrafast thermal relaxation S* --> S1. The rate constant of the relaxation does not depend on the solvent and on the presence of the amino acid side chain: the temperature dependences of photoionization quantum yield, obtained for TrpH and IndH in different solvents, practically coincide. The activation energy for the relaxation rate constant Er approximately 4.5 kJ/mol probably corresponds to intramolecular process or to the formation of the vibronically excited transient complex between photoexcited molecule and solvent molecules.

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2348868DOI Listing

Publication Analysis

Top Keywords

quantum yield
8
trph indh
8
rate constant
8
competition ultrafast
4
relaxation
4
ultrafast relaxation
4
relaxation photoionization
4
photoionization excited
4
excited prefluorescent
4
prefluorescent states
4

Similar Publications

Landau-Levich Scaling for Optimization of Quantum Dot Layer Morphology and Thickness in Quantum-Dot Light-Emitting Diodes.

ACS Nano

January 2025

Department of Chemical and Biomolecular Engineering, Lehigh University, 124 E. Morton Street, Bethlehem, Pennsylvania 18015, United States.

Quantum dot (QD) light-emitting diodes (QLEDs) are promising candidates for next-generation displays because of their high efficiency, brightness, broad color gamut, and solution-processability. Large-scale solution-processing of electroluminescent QLEDs poses significant challenges, particularly concerning the precise control of the active layer's thickness and uniformity. These obstacles directly impact charge transport, leading to current leakage and reduced overall efficiency.

View Article and Find Full Text PDF

Reducing aggregation caused quenching and enhancing stability is crucial in the fabrication of organic light-emitting diodes. Herein, we successfully fabricated blue-emitting coordination polymer glasses using perylene dye and a zinc-based coordination glass. The aggregation of perylene monomers in the solid state was significantly suppressed, and the hybrid glass demonstrated high stability and strong photoluminescent quantum yield (75.

View Article and Find Full Text PDF

The organic semiconductor Y6 has been extensively used as an acceptor in organic photovoltaic devices, yielding high efficiencies. Its unique properties include a high refractive index, intrinsic exciton dissociation, and barrierless charge generation in bulk heterojunctions. However, the direct impact of the crystal packing morphology on the photophysics of Y6 has remained elusive, hindering further development of heterojunction and homojunction devices.

View Article and Find Full Text PDF

Mixing different metal ions at the B site of ABX perovskites offers a promising approach for addressing challenges related to toxicity, stability and performance in optoelectronic applications. One such example is CsPbSnBr which addresses the toxicity issue posed by lead while allowing us to tune optoelectronic properties such as the band gap. In this work, nearly monodisperse CsPbSnBr quantum dots (QDs) were synthesized with variable Pb/Sn compositions, CsPbBr, CsPbSnBr and CsPbSnBr.

View Article and Find Full Text PDF

While CuS/TiO₂ has been previously synthesized and employed in a limited number of photodegradation studies, the current study investigated its effectiveness for TC degradation under UV-visible light irradiation. CuS is known to be a nontoxic, environmentally friendly material; hence, it has great potential as an alternative to CdS and CdSe, which are used conventionally as sensitizers. In this work, the CuS/TiO₂ photocatalysts achieved a maximum 95 % removal of TC at an initial concentration of 20 ppm, confirming the good utilization of active sites.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!