- School of Chemistry - Research Publications
School of Chemistry - Research Publications
Permanent URI for this collection
8 results
Filters
Reset filtersSettings
Statistics
Citations
Search Results
Now showing
1 - 8 of 8
-
ItemHighly Efficient Luminescent Solar Concentrators by Selective Alignment of Donor-Emitter FluorophoresZhang, B ; Gao, C ; Soleimaninejad, H ; White, JM ; Smith, TA ; Jones, DJ ; Ghiggino, KP ; Wong, WWH (AMER CHEMICAL SOC, 2019-04-23)Vertically aligning fluorophores to the surface of a waveguide is known to be an effective approach to improve the optical quantum efficiency (OQE) of luminescent solar concentrators (LSCs). While the chromophore alignment assists waveguiding of the emitted photons to the LSC edges, it also significantly reduces the light-harvesting properties of the LSC. We report here a fluorophore pair consisting of a sphere-shaped energy donor and a rod-shaped emitter that was incorporated in LSCs to provide selective fluorophore alignment to address the reduced incident-light absorption issue. A liquid-crystal polymer matrix was used to perpendicularly align the rod-shaped acceptors to a favorable orientation for light guiding, while the sphere-shaped donor was randomly oriented to maintain its light-absorbing properties. The OQE of LSC devices with this selectively aligned donor-acceptor fluorophore system is 78% without significant loss of light-harvesting capability.
-
ItemSingle Isomer of Indene-C70 Bisadduct-Isolation and Performance in Bulk Heterojunction Solar CellsWong, WWH ; Subbiah, J ; White, JM ; Seyler, H ; Zhang, B ; Jones, DJ ; Holmes, AB (AMER CHEMICAL SOC, 2014-02-25)
-
ItemMorphology Change and Improved Efficiency in Organic Photovoltaics via Hexa-peri-hexabenzocoronene TemplatesDam, HH ; Sun, K ; Hanssen, E ; White, JM ; Marszalek, T ; Pisula, W ; Czolk, J ; Ludwig, J ; Colsmann, A ; Pfaff, M ; Gerthsen, D ; Wong, WWH ; Jones, DJ (AMER CHEMICAL SOC, 2014-06-11)The morphology of the active layer in organic photovoltaics (OPVs) is of crucial importance as it greatly influences charge generation and transport. A templating interlayer between the electrode and the active layer can change active layer morphology and influence the domain orientation. A series of amphiphilic interface modifiers (IMs) combining a hydrophilic polyethylene-glycol (PEG) oligomer and a hydrophobic hexabenzocoronene (HBC) were designed to be soluble in PEDOT:PSS solutions, and surface accumulate on drying. These IMs are able to self-assemble in solution. When IMs are deposited on top of a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) film, they induce a morphology change of the active layer consisting of discotic fluorenyl-substituted HBC (FHBC) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). However, when only small amounts (0.2 wt %) of IMs are blended into PEDOT:PSS, a profound change of the active layer morphology is also observed. Morphology changes were monitored by grazing incidence wide-angle X-ray scattering (GIWAXS), transmission electron microscopy (TEM), TEM tomography, and low-energy high-angle angular dark-field scanning transmission electron microscopy (HAADF STEM). The interface modification resulted in a 20% enhancement of power conversion efficiency.
-
ItemRegioselective synthesis of fullerene multiadducts via tether-directed 1,3-dipolar cycloadditionZhang, B ; White, JM ; Jones, DJ ; Wong, WWH (ROYAL SOC CHEMISTRY, 2015)The regioselective synthesis of fullerene multiadducts was achieved from commercially available reagents in one pot over two steps. The configuration of the isolated regioisomers was determined using various NMR methods, UV-vis spectroscopy and electrochemical analysis with the structure of one isomer confirmed by single crystal X-ray analysis. Interesting variation in regioselectivity was observed when different amino acid reagents were used in the reactions. Theoretical calculations and additional experiments, such as deuterium exchange, led to a proposed mechanism for the regioselective product formation.
-
ItemEnergy Migration in Organic Solar Concentrators with a Molecularly Insulated Perylene DiimideBanal, JL ; Soleimaninejad, H ; Jradi, FM ; Liu, M ; White, JM ; Blakers, AW ; Cooper, MW ; Jones, DJ ; Ghiggino, KP ; Marder, SR ; Smith, TA ; Wong, WWH (AMER CHEMICAL SOC, 2016-06-23)
-
ItemHighly Fluorescent Molecularly Insulated Perylene Diimides: Effect of Concentration on Photophysical PropertiesZhang, B ; Soleimaninejad, H ; Jones, DJ ; White, JM ; Ghiggino, KP ; Smith, TA ; Wong, WWH (AMER CHEMICAL SOC, 2017-10-10)
-
ItemOne-pot selective synthesis of a fullerene bisadduct for organic solar cell applicationsZhang, B ; Subbiah, J ; Lai, Y-Y ; White, JM ; Jones, DJ ; Wong, WWH (ROYAL SOC CHEMISTRY, 2015)A single isomer of fullerene bisadduct, PC61PF, was obtained from commercially available fullerene derivative, PC61BM, in one pot over two steps. The tether-directed remote functionalization approach provided a very simple and fast method to produce a single isomer of fullerene bisadduct with good yield and easy purification. Bulk heterojunction organic solar cells containing the bisadduct was fabricated and tested.
-
ItemA molecular nematic liquid crystalline material for high-performance organic photovoltaicsSun, K ; Xiao, Z ; Lu, S ; Zajaczkowski, W ; Pisula, W ; Hanssen, E ; White, JM ; Williamson, RM ; Subbiah, J ; Ouyang, J ; Holmes, AB ; Wong, WWH ; Jones, DJ (NATURE PUBLISHING GROUP, 2015-01)Solution-processed organic photovoltaic cells (OPVs) hold great promise to enable roll-to-roll printing of environmentally friendly, mechanically flexible and cost-effective photovoltaic devices. Nevertheless, many high-performing systems show best power conversion efficiencies (PCEs) with a thin active layer (thickness is ~100 nm) that is difficult to translate to roll-to-roll processing with high reproducibility. Here we report a new molecular donor, benzodithiophene terthiophene rhodanine (BTR), which exhibits good processability, nematic liquid crystalline behaviour and excellent optoelectronic properties. A maximum PCE of 9.3% is achieved under AM 1.5G solar irradiation, with fill factor reaching 77%, rarely achieved in solution-processed OPVs. Particularly promising is the fact that BTR-based devices with active layer thicknesses up to 400 nm can still afford high fill factor of ~70% and high PCE of ~8%. Together, the results suggest, with better device architectures for longer device lifetime, BTR is an ideal candidate for mass production of OPVs.