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Related papers: A Quantum Yield Map for Synthetic Eumelanin

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We report absolute values for the radiative relaxation quantum yield of synthetic eumelanin as a function of excitation energy. These values were determined by correcting for pump beam attenuation and emission re-absorption in both…

Soft Condensed Matter · Physics 2007-05-23 Paul Meredith , Jenny Riesz

Previously reported excitation spectra for eumelanin are sparse and inconsistent. Moreover, these studies have failed to account for probe beam attenuation and emission reabsorption within the samples, making them qualitative at best. We…

Soft Condensed Matter · Physics 2007-05-23 Stephen Nighswander-Rempel , Jennifer Riesz , Joel Gilmore , Jacques Bothma , Paul Meredith

The development of new fluorescent molecules and dyes requires precise determination of their emission efficiency, which ultimately defines the potential of the developed materials. For this, the photoluminescence quantum yield (QY) is…

Instrumentation and Detectors · Physics 2018-07-27 Bart van Dam , Benjamin Bruhn , Gejza Dohnal , Katerina Dohnalova

The optical scattering coefficient of a dilute, well solubilised eumelanin solution has been accurately measured as a function of incident wavelength, and found to contribute less than 6% of the total optical attenuation between 210 and…

Biological Physics · Physics 2009-11-11 Jennifer Riesz , Joel Gilmore , Paul Meredith

Cis-trans isomerization in retinal, the first step in vision, is often computationally studied from a time dependent viewpoint. Motivation for such studies lies in coherent pulsed laser experiments that explore the isomerization dynamics.…

Chemical Physics · Physics 2014-02-19 T. V. Tscherbul , P. Brumer

Accurate characterization of quantum yield is crucial to the reconstruction of energy depositions in silicon at the eV scale. This work presents a new method for experimentally calculating quantum yield using vacuum UV-sensitive silicon…

For the development and optimization of novel light emitting materials, such as fluorescent proteins, dyes and semiconductor quantum dots (QDs), a reliable and robust analysis of the emission efficiency is crucial. The emission efficiency…

The krypton electroluminescence yield was studied, at room temperature, as a function of electric field in the gas scintillation gap. A large area avalanche photodiode has been used to allow the simultaneous detection of the…

Instrumentation and Detectors · Physics 2021-02-02 R. D. P. Mano , C. A. O. Henriques , F. D. Amaro , C. M. B. Monteiro

We have combined ab initio quantum chemistry calculations with a rate-equation formalism to analyze electroluminescence spectra in single-molecule junctions, measured recently by several groups in Scanning Tunneling Microscope setups. In…

Mesoscale and Nanoscale Physics · Physics 2010-05-20 Johannes S. Seldenthuis , Herre S. J. van der Zant , Mark A. Ratner , Joseph M. Thijssen

We perform the quantum yields in a multi-band quantum dot (QD) photocell via doping an intermediate band (IB) between the conduction band (CB) and valence band (VB). Under two different sub-band gap layouts, the output power has a prominent…

Mesoscale and Nanoscale Physics · Physics 2024-02-13 Shun-Cai Zhao , Qi-Xuan Wu

A gamma-ray line production calculation in astrophysics depends on i) the composition and energy source spectrum of the energetic particles, ii) the propagation model, and iii) the nuclear cross sections. The main difficulty for model…

Astrophysics · Physics 2009-11-07 E. Parizot , R. Lehoucq

We simulate the nonequilibrium steady state \textit{cis-trans} photoisomerization of retinal chromophore in rhodopsin based on a two-state-two-mode model coupled to a thermal environment. By analyzing the systematic trends within an…

Chemical Physics · Physics 2022-04-25 Chern Chuang , Paul Brumer

We propose a dynamic mechanism for the reversible regulation of photosynthesis in varying light environments. We employ a three-level quantum model to take into account the correlations between charge donors and charge acceptors immediately…

Biological Physics · Physics 2024-11-13 Guang Yang , Gen Tatara

When optically excited, iodine absorbs in the 490- to 650-nm visible region of the spectrum and, after radiative relaxation, it displays an emission spectrum of discrete vibrational bands at moderate resolution. This makes laser-induced…

Physics Education · Physics 2015-07-10 S. B. Bayram , M. V. Freamat

The photoisomerization reaction of the retinal chromophore in rhodopsin was computationally studied using a two-state two-mode model coupled to thermal baths. Reaction quantum yields at the steady state (10 ps and beyond) were found to be…

Quantum Physics · Physics 2021-07-13 Chern Chuang , Paul Brumer

The air fluorescence technique is used to detect ultra-high energy cosmic rays (UHECR), and to estimate their energy. Of fundamental importance is the photon yield due to excitation by electrons, in air of various densities and…

Astrophysics · Physics 2009-11-10 M. Nagano , K. Kobayakawa , N. Sakaki , K. Ando

Dispersion properties of metals and propagation of quantum bulk plasmon in the high photon energy regime are studied. The nonlocal dielectric permittivity of a metal is determined by the quantum plasma effects and is calculated by applying…

Optics · Physics 2014-10-23 M. Moaied , M. M. A. Yajadda , K. Ostrikov

Calculations of the cross sections of inelastic electron scattering $(e,e')$ on a nucleus in the multi-keV energy range strongly depend on the description of the screening of the nuclear Coulomb potential as well as on the deformation of…

Nuclear Theory · Physics 2022-02-14 F. Gobet , A. Ya. Dzyublik , G. Gosselin , V. Méot , M. Versteegen

The fluorescence quantum yield of bis-MSB, a widely used liquid scintillator wavelength shifter, was measured to study the photon absorption and re-emission processes in liquid scintillator. The re-emission process affects the photoelectron…

Instrumentation and Detectors · Physics 2015-11-19 Ding Xue Feng , Wen Liang Jian , Zhou Xiang , Ding Ya Yun , Ye Xing Chen , Zhou Li , Liu Meng Chao , Cai Hao , Cao Jun

The kinetic energy distributions of photo-electrons emitted from gold surfaces under illumination by UV-light close to the threshold are measured and analyzed. Samples are prepared as chemically clean through Ar-Ion sputtering and then…

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