Research team

Expertise

- Solubilisation, chirality separation and exo- and endohedral functionalisation of carbon nanotubes - Optical Spectroscopy (wavelength-dependent resonant Raman scattering spectroscopy, wavelength-dependent IR fluorescence-excitation spectroscopy, time-resolved absorption and fluorescence spectroscopy) - Hyperspectral fluorescence imaging -Electron Paramagnetic Resonance Spectroscopy - Optically-detected magnetic resonance spectroscopy

Spin Resonance and Time-Resolved Spectroscopy of Optically-Adressable Diradical Qubits (SPECTROBITS). 01/09/2024 - 31/08/2026

Abstract

In quantum sensing, capable of sensing small magnetic fields due to motion of electrons in e.g. neurons, quantum bits (qubits) are preferably operational at room temperature. In this respect, organic molecular qubits (MQBs) bring many advantages such as long coherence times, exact positioning of the qubit, tunability and scalability. Yet, the implementation of MQBs is obstructed by the lack of single-qubit readout and the so far unknown relationship between qubit performance and chemical structure. Recent progress in the synthesis of stable organic molecules with two unpaired electron spins in their ground electronic state, i.e. diradicals, leads to an uncharted market for MQBs. The main selling point resides in the possibility of controlling the spin-spin interactions via chemical synthesis, and the huge potential for single-qubit optical readout. I will investigate new organic diradicals spanning the whole range of spin-spin interactions to establish a direct relation between the spin-spin interaction and their performance as MQBs. By combining my expertise in diradical spectroscopy with the expertise of my supervisors in electron spin resonance and optically-detected magnetic resonance, I aim to develop initialization, readout and manipulation processes for these MQBs. An intensive collaboration with chemical synthesis groups and a theoretician warrants a novel route towards quantum sensing with MQBs.

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  • Research Project

Optically Addressable Trityl-Radical-based Molecular Qubits (OPTRIBITS) 01/07/2024 - 30/06/2027

Abstract

Quantum technologies are widely believed to fundamentally change society in the near future, and extraordinary effort is being expended towards this goal. However potentially insurmountable challenges may loom on the horizon, e.g., lack of scalability, lack of tailorability and lack of qubit positionability. In OPTRIBITS, we will exploit the fundamental advantages of paramagnetic molecules for application as spin-based qubits in quantum technologies. Molecules have been shown to possess long ensemble coherence times up to the millisecond regime, with figures of merit exceeding 10,000. Molecules are nanoscopic in size, allowing for integration into devices at high densities enabling miniturization of quantum devices. Molecules are highly tailorable in terms of spin values, spin level structures, and excited state properties, enabling their adaptation to specific quantum technological objectives. Interqubit interactions can be exquisitely controlled, due to the high degree of qubit positionability in few-qubit or ordered arrangements, leading to well-defined and potentially switchable interactions. The main issue preventing the widespread use of molecular qubits has been the lack of convenient single-entity readout. As a result, the vast majority of results on molecular qubits have been obtained by ensemble measurements featuring large numbers of identical qubit copies. This proposal aims to remove this drawback by developing optically addressable molecular qubits. Optical addressing has been amply demonstrated to allow single entity readout because of the single photon sensitivity of optical detectors. To this end, we will design, prepare and study robust molecular qubits, which have spin states that allow for inducing spin polarization by optical pumping and are highly luminescent to allow for optical readout. In a second step, we will work towards device integration by immobilizing the qubit architectures on surfaces or by creating hybrid structures with carbon nanomaterials.

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  • Research Project

3D Biofabricated high-perfoRmance dna-carbon nanotube dIgital electroniCKS (3D-BRICKS). 01/05/2023 - 30/04/2026

Abstract

Single-walled carbon nanotubes (SWCNTs) possess unique optical and electronic properties that depend critically on their exact chiral structure. By filling the hollow cores of the SWCNTs, new functionalities can be obtained, originating from the peculiar interaction of the encapsulants and the host SWCNTs. In this project, we will focus on filling SWCNTs with electron donor and acceptor molecules, that can result in n- and p-type doping of the host SWCNTs. Through the dependence on the ionization potential or electron affinity of the encapsulated molecules, it is expected that the doping level can be finely tuned by choosing the specific molecules (or a combination of different molecules) to be encapsulated. The development of reliable methods for SWCNT doping combined with chiral sorting methodologies, can lead to a breakthrough advancement in SWCNT-related applications, such as SWCNT-based field-effect transistors. The doped SWCNTs will be investigated by means of a wide range of experimental techniques, in particular EPR spectroscopy, that can directly access the doping level of the SWCNTs in a quantitative manner, and optical spectroscopic techniques, such as absorption spectroscopy, wavelength-dependent resonant Raman spectroscopy and infrared fluorescence-excitation spectroscopy and imaging

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  • Research Project

Organic spintronics based on intrinsically paramagnetic polymers. 01/11/2022 - 31/10/2025

Abstract

The weak spin-orbit interaction inherent to organic semiconductors makes them ideal candidates for spintronics applications. While typical spin lifetimes easily surpass those of their inorganic counterparts by several orders of magnitude, the main limitation in organic spin transporters is the spin diffusion length, often not exceeding 50 nm. It has now been established that spins in organic materials can be transported either by mobile charges or via spin exchange between localized polarons. The latter mechanism opens up an interesting new avenue toward longer spin diffusion lengths by increasing the intrinsic spin density of the materials. In 2019, record spin diffusion lengths of 1 um have been reported for the first time in a highly-doped polymer. In this project, I propose to investigate spin transport in paramagnetic polymers, a recently-discovered class of ultra-low-bandgap semiconductors exhibiting a triplet ground state and hence a large intrinsic spin density. Spin transport experiments will be performed in state-of-the-art spintronic devices based on spin pumping injection. In addition, the combination of electron paramagnetic resonance methods and supporting quantum-chemical computations will provide detailed information on spin delocalization and spin-spin-interactions. By expanding my study to a series of these polymers, structure-property relations can be elucidated and used to establish the fundamentals of spin transport in these innovative materials.

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  • Research Project

Optimizing carbon nanotube deposition as emissive layer in near-infrared organic light emitting diodes applying ultrasonic spray coating techniques; 01/11/2022 - 31/10/2024

Abstract

This is a strategic research project financed by the Research Foundation – Flanders (FWO). The objective is to study the integration of emissive carbon nanotubes in organic light emitting diodes. The focus of the project lies on the use of ultrasonic spray coating to produce thin films of carbon nanotubes.

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Functional Hybrids of Carbon Nanotubes. 01/10/2022 - 30/09/2027

Abstract

In this 5-year ZAPBOF project, I will investigate different functionalization routes for SWCNTs to enhance and diversify their opto-electronic properties. In particular I will aim at enhancing the SWCNT emission efficiency, by promoting triplet exciton emission, and at studying their interaction with long-lived radicals, combining optical spectroscopy with paramagnetic resonance spectroscopy. Finally, I will invest in the itneraction of SWCNTs with other one-dimensional layers, in so-called 1D heteronanotubes.

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  • Research Project

Steady-state and time-resolved fluorescence spectroscopy (FLUORATE). 01/06/2022 - 31/05/2024

Abstract

Optical materials are ubiquitous in present society. From the building blocks of displays and LEDs, to fibre optic communication for ultrafast internet, (plasmonic) nanostructures for photocatalysis, bulk heterojunctions for photovoltaics, probes for imaging, sensing and revealing reaction mechanisms in chemistry and catalysis and various nanostructures for nanophotonics applications. The in-depth knowledge on the nature and dynamics of the surface and bulk properties of these materials, such as the fate of electrons and holes that arise after optical excitation requires dedicated spectroscopic techniques that can reveal both steady-state and time-resolved properties of such materials. Fluorescence spectroscopy is one of the most versatile and sensitive techniques that can provide such information. Modern detectors are able to detect single photons that are emitted at time scales ranging from several picoseconds to seconds, and with energies spanning the entire UV, visible and NIR optical range. The system applied for is a versatile steady-state and time-resolved fluorescence spectrometer, that is highly modular and when combined with the already available infrastructure, provides a unique configuration allowing a wide range of experiments that provide information on a.o. ultrafast processes at picosecond timescales, delayed fluorescence from for example triplet states and with a sensitivity over a very broad wavelength range (200 – 1700nm) and accessibility to both ensemble and single-molecule detection from solutions, powders, nanoparticles, films and devices. The infrastructure will be applied in very different research fields, from photocatalysis to excitonic properties of nanomaterials, and from chemical reaction kinetics to photovoltaic and LED applications, which is also confirmed by the very diverse research topics of the 5 involved research teams.

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  • Research Project

Endohedral functionalisation of single-wall carbon nanotubes. 01/06/2022 - 31/05/2024

Abstract

Single-walled carbon nanotubes (SWCNTs) possess unique optical and electronic properties that depend critically on their exact chiral structure. By filling the hollow cores of the SWCNTs, new functionalities can be obtained, originating from the peculiar interaction of the encapsulants and the host SWCNTs. In this project, we will focus on filling SWCNTs with electron donor and acceptor molecules, that can result in n- and p-type doping of the host SWCNTs. Through the dependence on the ionization potential or electron affinity of the encapsulated molecules, it is expected that the doping level can be finely tuned by choosing the specific molecules (or a combination of different molecules) to be encapsulated. The development of reliable methods for SWCNT doping combined with chiral sorting methodologies, can lead to a breakthrough advancement in SWCNT-related applications, such as SWCNT-based field-effect transistors. The doped SWCNTs will be investigated by means of a wide range of experimental techniques, in particular EPR spectroscopy, that can directly access the doping level of the SWCNTs in a quantitative manner, and optical spectroscopic techniques, such as absorption spectroscopy, wavelength-dependent resonant Raman spectroscopy and infrared fluorescence-excitation spectroscopy and imaging

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  • Research Project

Filling and advanced spectroscopic characterisation of long single-wall carbon nanotubes. 01/11/2021 - 31/10/2025

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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  • Research Project

High-end electron paramagnetic resonance instrumentation for catalysis and materials characterization. 01/05/2020 - 30/04/2024

Abstract

Electron paramagnetic resonance (EPR) offers a unique tool for the characterization of paramagnetic systems found in biological and synthetic materials. It is used in very diverse fields, such as biology, chemistry, physics, medicine and materials sciences. EPR is a global name for many different techniques, of which the pulsed EPR spectroscopies are the most versatile ones, able to reveal very detailed structural information. The University of Antwerp hosts a pulsed and high-field EPR facility that is unique in Belgium. However, the basic continuous-wave EPR instrumentation that underlies this facility needs urgent upgrade. Moreover in recent years, the technical realization of arbitrary waveform generators (AWGs) with clock rates higher than a gigahertz has initiated a new era in EPR spectroscopy. These AWGs allow for novel experiments with shaped pulses through which more detailed information about the systems under study can be obtained. Use of these shaped pulses avails enormously increased sensitivity and spectral width. This is particularly important for the study of nanostructured materials and the detection of transiently formed active sites during catalysis, device operation or biological in-cell reactions, topics of major interest for the consortium. The requested extension of the EPR facility is essential to assure that EPR at UAntwerp remains at the forefront in this rapidly changing field.

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  • Research Project

TunabLe pulsed And continuouS-wavE laseR facility (T-LASER). 01/01/2020 - 31/12/2021

Abstract

T-LASER comprises the extension of a laser facility to a versatile wavelength-tunable pulsed and continuous-wave (CW) laser platform operating from the ultraviolet to the infrared range of the optical spectrum, for enabling a wide range of advanced spectroscopic techniques and laser-based applications – the key research capabilities of the ECM group. Thanks to a large fraction (78%) of co-funding, a laser platform will be built that is not only essential to all of ECM's ongoing research projects and its many collaborations, but actually establishes a world-wide unique laser facility. Moreover, this central laser platform will be complemented with a range of optical satellite setups that are already available (and already unique) and will be further developed. The versatility of the laser facility, both in pulse duration and wavelength tunability, will enable unprecedented optical experiments, such as widely continuously tunable resonance Raman scattering, and nonlinear optical scattering such as widely wavelength-tunable (second- and third-order) hyper-Rayleigh and hyper-Raman scattering. This will form a highly complementary set of unique techniques, making UAntwerp an extremely desirable partner for research groups active in the involved technologies, worldwide.

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  • Research Project

Structure-specific competitive surfactant interactions with carbon nanotubes: a hyperspectral route to their separation by diameter and chiral structure. 01/10/2019 - 30/09/2023

Abstract

This is a fundamental research project financed by the research council of the University of Antwerp through a DOCPRO4 BOF research grant. The project was funded after selection by the research council. The objective of this Research project is to advance fundamental scientific research.

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Chirality-defined sorting and optical characterization of double-wall carbon nanotubes. 01/10/2019 - 30/09/2022

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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  • Research Project

Hyperspectral imaging of the endo- and exohedral interactions of molecules with single-wall carbon nanotubes. 01/10/2019 - 30/09/2021

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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  • Research Project

Electrical and physical characterization of trap states at the SiC/gate dielectric interface in SiC metal-oxide-semiconductor field-effect transistors. 01/04/2019 - 31/03/2023

Abstract

This is a research project financed by the Vlaio agency for innovation and entrepreneurship (VLAIO - Vlaanderen). The project was subsidized after selection by the expert panel. The project is conducting in collaboration with Flemish Industry.

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  • Research Project

Functional Carbon Nanotube Nanohybrids: from Synthesis to Advanced Spectroscopic Characterization 01/01/2018 - 31/12/2021

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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Carbon nanomaterial enhanced optical fibres for biomedical imaging and sensing (CHARMING). 01/01/2018 - 31/12/2021

Abstract

Optical fibres are very well-known for their application in telecommunications. In the last decades, they have also become increasingly popular in biomedical applications, where they are used as very sensitive sensors to detect minute amounts of biological cells or as flexible light sources enabling in-vivo microscopy of biological tissue, and as such allow for early diagnosis of medical conditions. At the same time, new so-called 'nanocarbon' materials with very particular characteristics have emerged, i.e. graphene and carbon nanotubes. The former is made of a sheet-like single layer of carbon atoms, whilst the latter consists of nanoscale hollow tubes rolled-up from the same carbon sheet. They both feature unique mechanical, electrical and optical properties. CHARMING's objective is to exploit these exceptional properties and to supplement them with the proven cutting-edge potential of optical fibrebased sensors and imaging systems to produce a novel class of devices for detecting and visualizing cancer cells with unprecedented sensitivity. More specifically, CHARMING will research into nanocarbon equipped optical fibres enabling the detection of down to 10 cancer cells as well as imaging of proteins in a tumorous environment with a 10-fold better sensitivity compared to current systems. By delivering this technology, CHARMING aims to contribute to the advent of advanced fibre-based tools empowering early in-vivo cancer diagnosis.

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  • Research Project

Functional Hybrids of Carbon Nanotubes 01/10/2017 - 30/09/2022

Abstract

New functional hybrids of diverse molecules encapsulated within single-walled carbon nanotubes will be designed, synthesized and investigated by a combination of high-resolution optical spectroscopy and microscopy.

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Diameter-dependent phase transitions in one-dimensional arrays of molecules confined inside single-wall carbon nanotubes. 01/10/2017 - 30/09/2021

Abstract

The properties and functions of many systems in biology, geology, catalysis and nanofluidics are determined by the confinement of molecules in small nanochannels, e.g. nanoconfined water plays a vital role in selective transport through cell membranes. The hollow structure of single-walled carbon nanotubes (SWCNTs), with a wide range of atomically-precise diameters, smooth impermeable walls and a giant aspect ratio, forms an ideal model system to study the behavior of molecules confined in one dimension. In this project the vibrational and electronic transitions of SWCNTs will be exploited as ultrasensitive probes for the local molecular order of the encapsulated molecules. Wavelength-dependent automated resonant Raman scattering and fluorescence-excitation spectroscopy will be performed as a function of temperature to unravel the phase behavior of water and other molecules confined inside the SWCNTs. The in-depth characterization of these phase transitions combined with state-of-the-art molecular dynamics simulations will enhance the understanding of molecular confinement and will pave the way for the rational design of ultraselective filtermembranes, sensors, fuel cells and nanofluidics applications.

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Hyperspectral imaging of the endo- and exohedral interactions of molecules with single-wall carbon nanotubes. 01/10/2017 - 30/09/2019

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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  • Research Project

Order in one dimension: Functional hybrids of chiralitysorted carbon nanotubes (ORDERin1D). 01/05/2016 - 31/10/2021

Abstract

The hollow structure of carbon nanotubes (CNTs) with a wide range of diameters forms an ideal host system to study restricted diameter-dependent molecular transport and to achieve unique molecular order in one dimension. This project finances fundamental research in the framework of an ERC starting grant, under horizon 2020.

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Advanced in situ optical spectroscopy to unravel the separation of carbon nanotubes by diameter and chiral structure. 01/01/2016 - 31/12/2018

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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Synthesis, chirality sorting and advanced spectroscopy of functional nanohybrids of organic molecules inside carbon nanotubes. 01/10/2014 - 30/09/2017

Abstract

This is a fundamental research project financed by the Research Foundation – Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. The objective of the FWO's Research projects is to advance fundamental scientific research.

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Pioneering work in the field of processing, purification, separation, and spectroscopic characterization of carbon nanotubes and nanofunctional hybrids. 13/11/2013 - 31/12/2014

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

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Imaging and advanced spectroscopy of individual carbon nanotubes by IR fluorescence microscopy. 01/01/2013 - 31/12/2015

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. It involves the advanced spectroscopy of individual carbon nanotubes with IR fluorescence microscopy.

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Development of a set-up for single-molecule spectroscopy and imaging of individual carbon nanotubes 01/01/2012 - 31/12/2012

Abstract

Our state-of-the-art wavelength-dependent fluorescence excitation setup (previously used for bulk spectroscopy) will be adapted to study single-walled carbon nanotubes at the single molecule level, through the purchase of a high numerical aperture oil-immersion objective and an xyz-translation stage. Using a SiCCD camera, the nanotube dynamics and the filling-dynamics can be imaged and studied by optical spectroscopy.

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Advanced spectroscopy of empty and water-filled carbon nanotubes: Improved diameter sorting, exciton photophysics and one-dimensional molecular transport. 01/10/2011 - 30/09/2014

Abstract

Solubilization of single-walled carbon nanotubes (SWNTs) with bile salt surfactants allows for the sorting of the SWNTs by diameter using density gradient ultracentrifugation (DGU). Recent breakthroughs in the observation of water-filling and the sorting of empty and water-filled SWNTs will lift this sorting to a higher level, as the resolution in DGU is expected to increase drastically when using only empty and full-length SWNTs. These intact tubes possess superior optical properties, which is interesting for studying the very specific exciton photophysics of the nanotubes. The water-filling occurs even for very thin diameters, enabling the study of one-dimensional molecular transport inside the tubes and the different ordering and phase behavior of water (and other molecules) after confinement.

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Interaction between conjugated molecules and single-walled carbon nanotubes. 01/01/2007 - 31/12/2008

Abstract

Carbon nanotubes (CNTs) are very interesting as one-dimensional systems with metallic or semiconducting properties. The conduction and mobility of holes and electrons can be described in the same way. It is also possible to dope these nanotubes by inserting small molecules in the CNTs. These doped CNTs are very stable by exposure to air and the choice of the inserted molecule controls the degree of doping. This project will deal with two different subjects. First we will study the charge transfer from the conjugated molecules to the SW CNTs. This charge transfer is of great importance for the use of such composites in plastic solar cells. Second, we will consider doping of the CNTs by inserting different conjugated molecules inside the CNTs. Both systems wil be studied by optical spectroscopy, pulsed laserspectroscopy and electron paramagnetic resonance (EPR).

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Interaction between conjugated molecules and single-walled carbon nanotubes. 01/01/2005 - 31/12/2006

Abstract

Carbon nanotubes (CNTs) are very interesting as one-dimensional systems with metallic or semiconducting properties. The conduction and mobility of holes and electrons can be described in the same way. It is also possible to dope these nanotubes by inserting small molecules in the CNTs. These doped CNTs are very stable by exposure to air and the choice of the inserted molecule controls the degree of doping. This project will deal with two different subjects. First we will study the charge transfer from the conjugated molecules to the SW CNTs. This charge transfer is of great importance for the use of such composites in plastic solar cells. Second, we will consider doping of the CNTs by inserting different conjugated molecules inside the CNTs. Both systems wil be studied by optical spectroscopy, pulsed laserspectroscopy and electron paramagnetic resonance (EPR).

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Excitons and polarons in low bandgap polymers : optical generation and charge carrier separation. 01/10/2003 - 30/09/2004

Abstract

In this Ph.D-project research will be done on the characterisation of the properties of polymers with applications in plastic electronics, photovoltaic cells, organic light-emitting diodes and organic semi-conductors. In particular the characterisation of the photo-excited states (singlet and triplet states), the study of polarons and the study of the charge separation process, of vital importance in photovoltaics. The following techniques will be used; optical absorption and fluorescence spectroscopy, (L)EPR-spectroscopy ((Light induced) Electron Paramagnetic Resonance) and ODMR-spectroscopy (Optical Detected Magnetic Resonance) in X-band (~9.5GHz) as well as in W-band (~95GHz).

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  • Research Project