A5033850264- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Perovskite Materials and Applications
- Thin-Film Transistor Technologies
- Organic Light-Emitting Diodes Research
- Quantum Dots Synthesis And Properties
- Silicon and Solar Cell Technologies
- Fullerene Chemistry and Applications
- Microbial Fuel Cells and Bioremediation
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Chalcogenide Semiconductor Thin Films
- Molecular Junctions and Nanostructures
- Copper Interconnects and Reliability
- Polymer crystallization and properties
- Force Microscopy Techniques and Applications
- Electronic Packaging and Soldering Technologies
- Carbon Nanotubes in Composites
- solar cell performance optimization
- Integrated Circuits and Semiconductor Failure Analysis
- Synthesis and properties of polymers
- Photoreceptor and optogenetics research
- Copper-based nanomaterials and applications
- Analytical Chemistry and Sensors
- Advancements in Semiconductor Devices and Circuit Design
Hasselt University
2016-2025
Division of Materials Research
2018
New York University Press
2018
Cambridge University Press
2018
Agora
2017
IMEC
2005-2015
Material (Belgium)
1998-2015
Imec the Netherlands
2005-2014
University of Cambridge
2014
University of Wollongong
2014
Organolead halide perovskites currently are the new front-runners as light absorbers in hybrid solar cells, they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution-based fabrication routes. Long-term stability remains a major obstacle for application on an industrial scale. Here, it is demonstrated that significant decomposition effects occur during annealing of methylammonium lead triiode perovskite at 85 even inert atmosphere thus...
The open-circuit voltage $({V}_{oc})$ of polymer:fullerene bulk heterojunction solar cells is determined by the interfacial charge-transfer (CT) states between polymer and fullerene. Fourier-transform photocurrent spectroscopy electroluminescence spectra several blends are used to extract relevant molecular parameters. An analytical expression linking these properties ${V}_{oc}$ deduced shown be valid for photovoltaic devices comprising three commonly conjugated polymers blended with...
Organometal halide perovskites have tremendous potential as light absorbers for photovoltaic applications. In this work we demonstrate hybrid solar cells based on the mixed perovskite CH3NH3PbI2Cl in a thin film sandwich structure, with unprecedented reproducibility and generating efficiencies up to 10.8%. The successfulness of our approach is corroborated by experimental electronic structure determination perovskite. Hybrid organometal (e.g., CH3NH3PbI2Cl) are upcoming new players field...
Abstract Photocurrent generation by charge‐transfer (CT) absorption is detected in a range of conjugated polymer–[6,6]‐phenyl C 61 butyric acid methyl ester (PCBM) based solar cells. The low intensity CT bands are observed using highly sensitive measurement the external quantum efficiency ( EQE ) spectrum means Fourier‐transform photocurrent spectroscopy (FTPS). presence these implies formation weak ground‐state complexes studied polymer–fullerene blends. effective band gap E g material...
Abstract Intensive development of organometal halide perovskite solar cells has lead to a dramatic surge in power conversion efficiency up 20%. Unfortunately, the most efficient all contain (Pb), which is an unsettling flaw that leads severe environmental concerns and therefore stumbling block envisioning their large-scale application. Aiming for retention favorable electro-optical properties, tin (Sn) been considered likely substitute. Preliminary studies have however shown Sn-based...
In this article we report the weak but omnipresent electroluminescence (EL) from several types of organic polymer:fullerene bulk heterojunction solar cells biased in forward direction. The light emitted blends some commonly used polymers and fullerene molecule is significantly different that any pure materials comprising blend. lower energy blend EL found to correlate with both voltage onset emission open-circuit photovoltaic cell under illumination. We accordingly interpret originate...
We examine the significance of hot exciton dissociation in two archetypical polymer−fullerene blend solar cells. Rather than evolving through a bound charge transfer state, processes are proposed to convert excitons directly into free charges. But we find that internal quantum yields carrier photogeneration similar for both and direct excitation states. The yield, together with temperature dependence current−voltage characteristics, is consistent negligible impact from dissociation.
In this work, the phase diagram of poly(3-hexyl thiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blends is measured by means standard modulated temperature differential scanning calorimetry. Blends were made solvent-casting from chlorobenzene, as cast toluene or 1,2-dichlorobenzene prove to retain effects segregation during casting, hindering determination diagram. The film morphology P3HT/PCBM chlorobenzene results a dual crystallization behavior, in which each...
Abstract Evidence is presented for the formation of a weak ground‐state charge‐transfer complex in blend films poly[9,9‐dioctylfluorene‐ co ‐ N ‐(4‐methoxyphenyl)diphenylamine] polymer (TFMO) and [6,6]‐phenyl‐C 61 butyric acid methyl ester (PCBM), using photothermal deflection spectroscopy (PDS) photoluminescence (PL) spectroscopy. Comparison this with other polyfluorene polymer/PCBM blends shows that appearance correlated to ionization potential polymer, but not optical gap or surface...
A new ordered structure of the C60 derivative PCBM ([6-6]-phenyl C61-butyric acid methyl ester) is obtained in thin films based on blend PCBM:regioregular P3HT (poly(3-hexylthiophene)). Rapid formation needlelike crystalline structures a few micrometers up to 100 μm size demonstrated by submitting blended an appropriate thermal treatment. These can grow out 2D network needles and, specific cases, spectacular fans. Key parameters tune dimensions and spatial distribution are ratio annealing...
This letter reports on highly sensitive optical absorption measurements organic donor-acceptor solar cells, using Fourier-transform photocurrent spectroscopy (FTPS). The spectra cover an unprecedented dynamic range of eight to nine orders magnitude making it possible detect defect and disorder related sub-band gap transitions. Direct fully encapsulated cells with active layer poly[2-methoxy-5-(3′,7′-dimethyl-octyloxy)]-p-phenylene-vinylene:(6,6)-phenyl-C61-butyric-acid (1:4 weight ratio)...
Efforts to increase the relative permittivities of organic semiconducting materials and their effect on solar cell performance are evaluated.
Efficient fibre formation for all regioregular poly(3-alkylthiophene)s (P3ATs) with alkyl chain lengths (A) between 3 and 9 carbon atoms has been accomplished in several solvents. It was observed that the aliphatic (chlorinated) aromatic hydrocarbon solvents used, solvent refractive index offers some rationale to predict feasibility of a formation. The fibres were separated from remaining non-organised polymer by centrifugation. This enabled characterisation isolated function length TEM,...
Abstract Biological electron transport is classically thought to occur over nanometre distances, yet recent studies suggest that electrical currents can run along centimetre-long cable bacteria. The phenomenon remains elusive, however, as have not been directly measured, nor the conductive structures identified. Here we demonstrate bacteria conduct electrons centimetre distances via highly fibres embedded in cell envelope. Direct electrode measurements reveal nanoampere intact filaments up...
Electrical transport properties of poly (3-hexylthiophene) (P3HT) (6,6)-phenyl C61-butyric acid methyl ester (PCBM) solar cells, with and without encapsulation, have been investigated analyzed using admittance spectroscopy capacitance voltage measurements at different temperatures. The clearly reveals two defect states activation energies 53 100 meV, a concentration ten times higher in the unencapsulated sample. These defects seem to strong effect on charge cell performance when they are...
Organometal trihalide perovskite solar cells arguably represent the most auspicious new photovoltaic technology so far, as they possess an astonishing combination of properties. The impressive and brisk advances achieved far bring forth highly efficient solution processable cells, holding great promise to grow into a mature that is ready be embedded on large scale. However, vast majority state-of-the-art contains dense TiO2 electron collection layer requires high temperature treatment...
Abstract Long-distance extracellular electron transfer has been observed in Gram-negative bacteria and plays roles both natural engineering processes. The can be mediated by conductive protein appendages (in short unicellular such as Geobacter species) or cell envelopes filamentous multicellular cable bacteria). Here we show that Lysinibacillus varians GY32, a Gram-positive bacterium, is capable of bidirectional transfer. In microbial fuel cells, L. form centimetre-range cellular networks...
Abstract Filamentous cable bacteria display long-range electron transport, generating electrical currents over centimeter distances through a highly ordered network of fibers embedded in their cell envelope. The conductivity these periplasmic wires is exceptionally high for biological material, but chemical structure and underlying transport mechanism remain unresolved. Here, we combine high-resolution microscopy, spectroscopy, imaging on individual bacterium filaments to demonstrate that...