A5031774432- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Perovskite Materials and Applications
- Thin-Film Transistor Technologies
- Molecular Junctions and Nanostructures
- Fullerene Chemistry and Applications
- Force Microscopy Techniques and Applications
- Surface Chemistry and Catalysis
- Carbon Nanotubes in Composites
- Advanced Chemical Physics Studies
- Porphyrin and Phthalocyanine Chemistry
- Solar Thermal and Photovoltaic Systems
- Synthesis and Properties of Aromatic Compounds
- Photovoltaic System Optimization Techniques
- Advanced Electron Microscopy Techniques and Applications
- Machine Learning in Materials Science
- Nanowire Synthesis and Applications
- Advanced Photocatalysis Techniques
- nanoparticles nucleation surface interactions
- solar cell performance optimization
- Surface and Thin Film Phenomena
- Solar Radiation and Photovoltaics
Imperial College London
2012-2020
University of Washington
2017-2020
Seattle University
2018
Kensington Health
2016
Transnational Press London
2016
Plastic Electronics (Netherlands)
2014
The active layer in a solution processed organic photovoltaic device comprises light absorbing electron donor semiconductor, typically polymer, and an accepting fullerene acceptor. Although there has been huge effort targeted to optimize the absorbing, energetic, transport properties of material, fullerenes remain as exclusive acceptor all high performance devices. Very recently, some new non-fullerene acceptors have demonstrated outperform comparative This Account describes this progress,...
Abstract Solution-processed organic photovoltaics (OPV) offer the attractive prospect of low-cost, light-weight and environmentally benign solar energy production. The highest efficiency OPV at present use low-bandgap donor polymers, many which suffer from problems with stability synthetic scalability. They also rely on fullerene-based acceptors, themselves have issues cost, limited spectral absorption. Here we a new non-fullerene acceptor that has been specifically designed to give improved...
Non-fullerene acceptors with optimized energy levels enable 10% efficient solar cells reduced voltage losses <0.6 V.
A novel small molecule, FBR, bearing 3-ethylrhodanine flanking groups was synthesized as a nonfullerene electron acceptor for solution-processed bulk heterojunction organic photovoltaics (OPV). straightforward synthesis route employed, offering the potential large scale preparation of this material. Inverted OPV devices employing poly(3-hexylthiophene) (P3HT) donor polymer and FBR gave power conversion efficiencies (PCE) up to 4.1%. Transient steady state optical spectroscopies indicated...
In this review, we describe and discuss recent advances in the performance of polymeric semiconductors organic field effect transistors (OFETs). Design concepts such as short intermolecular contacts, low conformational disorder, side chain optimization, noncovalent interactions have all been successfully employed to improve charge carrier mobility polymer thin films. The relationship between molecular design, film microstructure, electrical has exemplified by a range thiophene, bridged fused...
The design, synthesis, and characterization of a series diketopyrrolopyrrole-based copolymers with different chalcogenophene comonomers (thiophene, selenophene, tellurophene) for use in field-effect transistors organic photovoltaic devices are reported. effect the heteroatom substitution on optical, electrochemical, properties charge carrier mobilities these polymers is discussed. results indicate that by increasing size chalcogen atom (S < Se Te), polymer band gaps narrowed mainly due to...
Abstract Nonfullerene acceptors (NFAs) in blends with highly crystalline donor polymers have been shown to yield particularly high device voltage outputs, but typically more modest quantum yields for photocurrent generation as well often lower fill factors (FF). In this study, we employ transient optical and optoelectronic analysis elucidate the determining FF of polymer PffBT4T‐2OD promising NFA FBR or widely studied fullerene acceptor PC 71 BM. Geminate recombination losses, measured by...
Abstract Organic semiconductors are in general known to have an inherently lower charge carrier mobility compared their inorganic counterparts. Bimolecular recombination of holes and electrons is important loss mechanism can often be described by the Langevin model. Here, device physics bulk heterojunction solar cells based on a nonfullerene acceptor (IDTBR) combination with poly(3‐hexylthiophene) (P3HT) elucidated, showing unprecedentedly low bimolecular rate. The high fill factor observed...
A review on organic photoelectrochemical water splitting cells giving perspective promising device architectures and materials.
Two electron-deficient truxenone derivatives are designed and synthesised for organic photovoltaic applications. The promise of this class compounds as acceptor materials is illustrated by the fabrication efficient bilayer solar cells with a subphthalocyanine (SubPc) donor, clearly outperforming reference soluble fullerene derivative acceptor.
Abstract The efficiency of organic photovoltaic (OPV) cells is rapidly increasing. However, many the highest performance OPV devices are also most unstable, including two widely used benzodithiophene‐co‐thieno[3,4‐b]thiophene polymers, PTB7 and PTB7‐Th. Here it shown that both choice pendant side chain, solvents for film deposition, have an important effect on active layer stability. Specifically, polymers with alkylthienyl chains found to be less stable than alkoxy chains. Secondly, high...
We report the synthesis of two barbiturate end-capped non-fullerene acceptors and demonstrate their efficient function in high voltage output organic solar cells. The acceptor with lower LUMO level is shown to exhibit suppressed geminate recombination losses, resulting enhanced photocurrent generation higher overall device efficiency.
A series of electron-deficient truxenone derivatives are investigated as fullerene alternatives in organic photovoltaic applications.
Abstract The temperature‐dependent aggregation behavior of PffBT4T polymers used in organic solar cells plays a critical role the formation favorable morphology fullerene‐based devices. However, there is little investigation into impact donor/acceptor ratio on tuning, especially for nonfullerene acceptors (NFAs). Herein, influence composition reported blends PffBT4T‐2DT with two NFAs, O‐IDTBR and O‐IDFBR. monotectic phase inferred from differential scanning calorimetry provides qualitative...
We describe an open-source and widely adaptable Python library that recognizes morphological features domains in images collected via scanning probe microscopy. π-Conjugated polymers (CPs) are ideal for evaluating the Materials Morphology (m2py) because of their wide range morphologies feature sizes. Using thin films nanostructured CPs, we demonstrate functionality a general m2py workflow. apply numerical methods to enhance signals by probe, followed Principal Component Analysis (PCA) reduce...
Solar cells based on blends of the donor polymer, P3HT, with nonfullerene acceptor, O-IDTBR, have been shown to exhibit promising efficiencies and stabilities for low-cost organic photovoltaic devices. We focus herein charge separation recombination dynamics in such By employing selective wavelength excitations P3HT we show that photoexcitation results lower internal quantum efficiency (IQE) photocurrent generation than observed O-IDTBR. Transient absorption photoluminescence quenching...
Truxenone on Cu (111) shows two packing motifs which exist at low and high coverage, coexist intermediate coverage.
The surface structure of partially fluorinated truxenone (F<sub>3</sub>-truxenone) molecules on Cu (111) has been probed using a combination scanning tunneling microscopy (STM) and low energy electron diffraction (LEED).