A5003395138- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Thin-Film Transistor Technologies
- Silicon and Solar Cell Technologies
- Perovskite Materials and Applications
- Fullerene Chemistry and Applications
- Augmented Reality Applications
- solar cell performance optimization
- Chalcogenide Semiconductor Thin Films
- Semiconductor materials and interfaces
- Surgical Simulation and Training
- Anatomy and Medical Technology
- Quantum Dots Synthesis And Properties
- Organic Light-Emitting Diodes Research
- Force Microscopy Techniques and Applications
- Photovoltaic System Optimization Techniques
- Carbon Nanotubes in Composites
- Molecular Junctions and Nanostructures
- Optical measurement and interference techniques
- 3D Surveying and Cultural Heritage
- Nanowire Synthesis and Applications
- Luminescence and Fluorescent Materials
- Robotics and Sensor-Based Localization
- Polymer Nanocomposite Synthesis and Irradiation
- EEG and Brain-Computer Interfaces
Friedrich Schiller University Jena
2016-2025
Michigan State University
2023
King Abdullah University of Science and Technology
2022
Central South University
2022
Offenburg University of Applied Sciences
2014-2021
InfraTec (Germany)
2020
Institut Català de Nanociència i Nanotecnologia
2019
Division of Materials Research
2018
New York University Press
2018
Cambridge University Press
2018
Within the different organic photovoltaic devices conjugated polymer/fullerene bulk heterojunction approach is one of foci today's research interest. These are highly dependent on solid state nanoscale morphology two components (donor/acceptor) in photoactive layer. The need for finely phase separated polymer–fullerene blends expressed by limited exciton diffusion length present semiconductors. Typical distances that these photo-excitations can travel within a pristine material around 10–20...
Abstract Improving the long-term stability of perovskite solar cells is critical to deployment this technology. Despite great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters reported. It therefore challenging reproduce compare results thereby develop a deep understanding degradation mechanisms. Here, we report consensus between researchers field for testing cell stability, which are based International Summit Organic...
Abstract The relation between the nanoscale morphology and associated device properties in conjugated polymer/fullerene bulk‐heterojunction “plastic solar cells” is investigated. We perform complementary measurements on solid‐state blends of poly[2‐methoxy‐5‐(3,7‐dimethyloctyloxy)]‐1,4‐phenylenevinylene (MDMO‐PPV) soluble fullerene C 60 derivative 1‐(3‐methoxycarbonyl) propyl‐1‐phenyl [6,6]C 61 (PCBM), spin‐cast from either toluene or chlorobenzene solutions. characterization nanomorphology...
Abstract The evolution of nanomorphology within thin solid‐state films poly(3‐alkylthiophene):[6,6]‐phenyl‐C 61 butyric acid methyl ester (P3AT:PCBM) blends during the film formation and subsequent thermal annealing is reported. In detail, influence P3AT's alkyl side chain length on polymer/fullerene phase separation discussed. Butyl, hexyl, octyl, decyl, dodecyl groups are investigated. All P3ATs used were regioregular. To elucidate nanomorphology, atomic force microscopy (AFM), X‐ray...
Abstract The preparation of 27 different derivatives C 60 and 70 fullerenes possessing various aryl (heteroaryl) and/or alkyl groups that are appended to the fullerene cage via a cyclopropane moiety their use in bulk heterojunction polymer solar cells is reported. It shown even slight variations molecular structure compound can cause significant change its physical properties, particular solubility organic solvents. Furthermore, derivative strongly affects morphology composite with...
Abstract The performance of polymer solar cells (PSC) strongly depends on the 3D morphological organization donor and acceptor compounds within bulk heterojunction active layer. technique electron tomography is a powerful tool for studying morphology layers composed poly(3‐hexylthiophene) (P3HT) fullerene derivative ([6,6]‐phenyl‐C61‐butyric acid methyl ester; PCBM), especially to quantify amount distribution fibrillar P3HT nanocrystals throughout volume In this study, used characterize...
We conducted a comprehensive Kelvin probe force microscopy (KPFM) study on classical organic solar cell system consisting of MDMO-PPV/PCBM blends. The KPFM method yields the information topography and local work function at nanometer scale. Experiments were performed either in dark or under cw laser illumination 442 nm. identified distinct differences energetics surface chlorobenzene toluene cast blend films. Together with high-resolution scanning electron (SEM) experiments we able to...
The morphological stabilization of donor–acceptor blends for bulk heterojunction solar cells can be achieved by cross-linking the small molecular phase in polymer matrix using a polymerizable fullerene derivative. In comparative study morphology polymer–fullerene blend films was investigated poly(3-hexylthiophene) (P3HT) as and C61-butyric acid methyl ester (PCBM) or newly synthesized derivative, glycidol ester, PCBG, acceptor molecule, respectively. Changes nanomorphology due to heat...
The photophysical properties of a new dyad molecule composed covalently linked Zn-phthalocyanine (antenna/donor) and C60 derivative (acceptor) have been investigated. We report experimental evidence long-lived charge separation in the solid state with lifetime several orders magnitude higher than solution. Such long lifetime, unusual for phthalocyanine–fullerene dyads, is basis possible photovoltaic applications. A first demonstration working solar cell using dyads as active material...
The use of doped wide-gap charge transport layers with high conductivity and low absorption in the visible range enables one to achieve internal quantum efficiencies optimize devices respect optical interference effects. Here, it is shown that this architecture particularly useful for stacking several cells on top each other. doping eases recombination majority carriers at interface between cells, whereas centers are hidden excitons minority carriers. By two p-i-n both a...
The performance of organic solar cells consisting multiple layers, which are a few hundred nanometers thick, is determined by strong optical interference effects. In order to model their and photoelectrical behavior, we the constants all components this system. This was done fitting dielectric functions reflection transmission spectra layers in cell device. We put special emphasis on understanding behavior photoactive bulk heterojunction film, consists composite semiconducting polymers with...
During the last few decades, and in some cases only years, novel thin‐film photovoltaic (PV) technologies such as dye‐sensitized solar cells (DSSC), organic (OPV), and, more recently, perovskite‐based (PSC) have been growing maturity with respect to device performance stability. Together new material systems, architectures also introduced. Both parameters will an effect on overall In order improve understanding of degradation effects how they can be prevented, stress testing under different...
The investigation of degradation seven distinct sets (with a number individual cells n ≥ 12) state the art organic photovoltaic devices prepared by leading research laboratories with combination imaging methods is reported. All have been shipped to and degraded at Risø DTU up 1830 hours in accordance established ISOS-3 protocols under defined illumination conditions. Imaging device function different stages was performed laser-beam induced current (LBIC) scanning; luminescence imaging,...
This article reports on the synthesis, characterization and properties of a series anthracene−containing poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene)s (PPE−PPV) copolymers with general constitutional unit (Ph−C≡C−Anthr−C≡C−Ph−CH═CH−Ph−CH═CH−)n denoted AnE-PV. Solely linear (AnE-PVaa, -ad, -ae) solely branched (AnE-PVbb) as well mixed (AnE-PVab, -ac, -ba, -cc) alkoxy side chains were grafted to backbone in order tune π−π-stacking ability materials. It has been possible...
Seven distinct sets (n ≥ 12) of state the art organic photovoltaic devices were prepared by leading research laboratories in a collaboration planned at Third International Summit on Organic Photovoltaic Stability (ISOS-3). All shipped to RISØ DTU and characterized simultaneously up 1830 h accordance with established ISOS-3 protocols under three illumination conditions: accelerated full sun simulation; low level indoor fluorescent lighting; dark storage daily measurement simulation. Three...
We report on the degradation of organic photovoltaic (OPV) cells in both indoor and outdoor environments. Eight different research groups contributed state art OPV to be studied at Pomona College. Power conversion efficiency fill factor were determined from IV curves collected regular intervals over six eight months. Similarly prepared devices measured indoors, outdoors, after dark storage. Device architectures are compared. Cells kept indoors performed better than outdoors due lack...
The development of non-fullerene acceptors (NFAs) has facilitated the realization efficient organic solar cells (OSCs) with minimal burn-in losses and excellent long-term stability. However, role NFA molecular structures on device stability remains unclear, limiting commercialization NFA-based OSCs. Herein, photostability 10 OSC devices, fabricated various NFAs (O-IDTBR, EH-IDTBR, ITIC, ITIC-M) blended donor polymers (PTB7-Th, PffBT4T-2OD, PBDB-T), is investigated. O-IDTBR EH-IDTBR form...
Abstract Transparent conductive electrodes (TCEs) are key components of photovoltaic devices. Being transparent, they allow light to enter the device, and being conductive, photocurrent generated be drawn into outer electric circuit. Ideally, TCEs exhibit maximum transmission conductivity at same time. However, both properties have balanced. Depending on material system, selection most suitable TCE is crucial assessed by so‐called figures‐of‐merit (FOM). Here, a novel exact FOM that...