Publications related to Quantum yield

Ultraviolet Superradiance from Mega-Networks of Tryptophan in Biological Architectures

Majed Chergui, Katrin Elisabeth Oberhofer

Networks of tryptophan (Trp)& horbar;an aromatic amino acid with strong fluorescence response & horbar;are ubiquitous in biological systems, forming diverse architectures in transmembrane proteins, cytoskeletal filaments, subneuronal elements, photorecepto ...

Amer Chemical Soc2024

Symmetry and Rigidity for Boosting Erbium-Based Molecular Light-Upconversion in Solution

Jean-Claude Bünzli, Alexandre Fürstenberg

Previously limited to highly symmetrical homoleptic triple-helical complexes [Er(Lk)3]3+, where Lk are polyaromatic tridentate ligands, single-center molecular-based upconversion using linear optics and exploiting the excited-state absorption mechanism (ES ...

Wiley-VCH Verlag GmbH2023

DNA-Liposome Hybrid Carriers for Triggered Cargo Release

Diana Kornelia Morzy

The design of simple and versatile synthetic routes to accomplish triggered-release properties in carriers is of particular interest for drug delivery purposes. In this context, the programmability and adaptability of DNA nanoarchitectures in combination w ...

AMER CHEMICAL SOC2022

Thiazole Boron Difluoride Dyes with Large Stokes Shift, Solid State Emission and Room-Temperature Phosphorescence

Jieping Zhu, Wei Wang, Shuo Tong

The small Stokes shift and weak emission in the solid state are two main shortcomings associated with the boron-dipyrromethene (BODIPY) family of dyes. This study presents the design, synthesis and luminescent properties of boron difluoro complexes of 2-ar ...

WILEY-V C H VERLAG GMBH2022

Block Copolymer Stabilized Liquid Nanodroplets Facilitate Efficient Triplet Fusion-Based Photon Upconversion in Solid Polymer Matrices

Felipe Andres Saenz Padilla

Sensitized triplet-triplet annihilation-based photon upconversion is a photo-physical process that affords anti-Stokes-shifted emission after annihilation of two metastable triplet excitons of an emitter dye and the formation of a fluorescent singlet state ...

AMER CHEMICAL SOC2021

Detection and Quantification of Nonlabeled Polystyrene Nanoparticles Using a Fluorescent Molecular Rotor

Florian Frédéric Vincent Breider, Angélique Emmanuelle Moraz

Plastic pollution has reached alarming levels in recent years. While macro- and microplastic pollution are attested and studied since the 1970s, much less is known about the associated nanoscopic fragments. Due to their ability to cross biological barriers ...

2021

Critical role of H-aggregation for high-efficiency photoinduced charge generation in pristine pentamethine cyanine salts

Jacques-Edouard Moser, Frank Nüesch, George Cameron Fish, Juan Manuel Moreno Naranjo

The mechanism of photoinduced symmetry-breaking charge separation in solid cyanine salts at the base of organic photovoltaic and optoelectronic devices is still debated. Here, we employ femtosecond transient absorption spectroscopy (TAS) to monitor the cha ...

2021

Optical properties and photochemical production of hydroxyl radical and singlet oxygen after ozonation of dissolved organic matter

Urs von Gunten, Frank Jonathan Leresche

This study focuses on the effects of ozonation on the optical and photochemical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in light absorption properties of DOM was observed concomitantly with a large increase in singlet oxyge ...

ROYAL SOC CHEMISTRY2021

Simplified Instrument Calibration forWide-FieldFluorescence Resonance Energy Transfer (FRET) Measured by the Sensitized Emission Method

Forster (or fluorescence) resonance energy transfer (FRET) is a quantifiable energy transfer in which a donor fluorophore nonradiatively transfers its excitation energy to an acceptor fluorophore. A change in FRET efficiency indicates a change of proximity ...

2021

Ultrafast Photoelectron and Optical Spectroscopies of Photoinduced Processes in Molecular Systems in Solution

Luca Longetti

Investigating molecular excitations with femtosecond time resolution is of pivotal importance to understand the out-of-equilibrium processes taking place in molecular systems upon light absorption. The photochemistry of solvated species is heavily determin ...

EPFL2020

Ultra-broadband time-resolved THz spectroscopy of perovskites and nanomaterials

Andrés Burgos Caminal

The fundamental study of charge carrier dynamics has been shown to be of great interest for optoelectronics, paving the way forward for future developments. Often, some of the key processes that determine the photophysics of a material occur on very short ...

EPFL2020

Effects of Ozone on the Photochemical and Photophysical Properties of Dissolved Organic Matter

Urs von Gunten, Frank Jonathan Leresche, Silvio Canonica

This study focused on the effects of ozonation on the photochemical and photophysical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in DOM absorbance was observed in parallel with an increase in singlet oxygen (O-1(2)) and fluore ...

AMER CHEMICAL SOC2019

Non-equilibrium dynamics of di-platinum complexes and molecular dyes in solution: Insights from transient absorption and two-dimensional Fourier transform spectroscopy

Lars-Hendrik Mewes

Unraveling the interplay between electronic- and vibrational degrees of freedom on the earliest time scales of physical, chemical and biological processes is crucial to gaining insight into the mechanisms that govern the world around us, since it is during ...

EPFL2019

Efficient intersystem crossing in 2-aminopurine riboside probed by femtosecond time-resolved transient vibrational absorption spectroscopy

Rebecca Ann Ingle, Hugo Jean Baptiste Marroux

The photophysical dynamics of 2-aminopurine riboside (2APr) in CHCl3 have been studied following excitation at (pump) = 310 nm by means of femtosecond transient vibrational absorption spectroscopy (TVAS) aided by quantum chemical density functional theory ...

ROYAL SOC CHEMISTRY2018

Ozone and chlorine reactions with dissolved organic matter - Assessment of oxidant-reactive moieties by optical measurements and the electron donating capacities

Urs von Gunten

Oxidation processes are impacted by the type, concentration and reactivity of the dissolved organic matter (DOM). In this study, the reactions between various types of DOM (Suwannee River fulvic acid (SRFA), Nordic Reservoir NOM (NNOM) and Pony Lake fulvic ...

2018

Boosting the performance of Cu2O photocathodes for unassisted solar water splitting devices

Linfeng Pan, Jinhyun Kim, Ulf Anders Hagfeldt, Jingshan Luo, Matthew Thomas Mayer, Amita Ummadisingu, Minkyu Son

Although large research efforts have been devoted to photoelectrochemical (PEC) water splitting in the past several decades, the lack of efficient, stable and Earth-abundant photoelectrodes remains a bottleneck for practical application. Here, we report a ...

2018

TDDFT-Based Spin-Orbit Couplings of 0D, 1D, and 2D Carbon Nanostructures: Static and Dynamical Effects

Ivano Tavernelli

Carbon nanostructures (CNS) constitute an important class of materials derived from graphene that share remarkable photophysical and photochemical properties of potential interest for a number of technological applications, ranging from electron transport ...

Amer Chemical Soc2017

Mechanism of ultrafast non-reactive deactivation of the retinal chromophore in non-polar solvents

Goran Zgrablic

The photoisomerization of the all-trans protonated Schiff base of retinal (SBR+) in solution is highly inefficient. The present theoretical and experimental investigation aims at disclosing the mechanisms of ultrafast, non-reactive relaxation of SBR+ that ...

Royal Soc Chemistry2017

Phototransformation of Acesulfame K in surface waters: Comparison of two techniques for the measurement of the second-order rate constants of indirect photodegradation, and modelling of photoreaction kinetics

Stefanos Giannakis

By use of photochemical modelling we show that acesulfame K (ACE) can undergo photodegradation in surface waters, mainly by reaction with (OH)-O-center dot and possibly (CDOM)-C-3* (the triplet states of chromophoric dissolved organic matter). With the pos ...

Elsevier2017

Dynamics of Electronic and Ionic Charges in Cyanine Organic Semiconductor Devices

Sandra Christina Jenatsch

Organic semiconductor materials have been widely applied in optoelectronic devices to replace their inorganic counterparts and explore new fields of applications. Due to their high extinction coefficients, chemical tunability and solubility, cyanine dyes a ...

EPFL2017