| 1. |
- Bliss, Martin, et al.
(författare)
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Spectral Response Measurements of Perovskite Solar Cells
- 2019
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Ingår i: IEEE Journal of Photovoltaics. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2156-3381 .- 2156-3403. ; 9:1, s. 220-226
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Tidskriftsartikel (refereegranskat)abstract
- A new spectral response (SR) measurement routine is proposed that is universally applicable for all perovskite devices. It is aimed at improving measurement accuracy and repeatability of SR curves and current-voltage curve spectral mismatch factor (MMF) corrections. Frequency response, effects of preconditioning as well as dependency on incident light intensity and voltage load on SR measurements are characterized on two differently structured perovskite device types. It is shown that device preconditioning affects the SR shape, causing errors in spectral MMF corrections of up to 0.8% when using a reference cell with a good spectral match and a class A solar simulator. Wavelength dependent response to incident light intensity and voltage load is observed on both device types, which highlights the need to measure at short-circuit current and maximum power point to correct spectral mismatch. The method with recommendations given ensures that the correct measurement conditions are applied and measurements are corrected for instability in performance.
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| 2. |
- Clarke, Andrew J., et al.
(författare)
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Non-fullerene acceptor photostability and its impact on organic solar cell lifetime
- 2021
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Ingår i: Cell Reports Physical Science. - : Elsevier. - 2666-3864. ; 2:7
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Tidskriftsartikel (refereegranskat)abstract
- The development of non-fullerene acceptors (NFAs) has facilitated the realization of efficient organic solar cells (OSCs) with minimal burn-in losses and excellent long-term stability. However, the role of NFA molecular structures on device stability remains unclear, limiting commercialization of NFA-based OSCs. Herein, the photostability of 10 OSC devices, fabricated with various NFAs (O-IDTBR, EH-IDTBR, ITIC, and ITIC-M) blended with donor polymers (PTB7-Th, PffBT4T-2OD, and PBDB-T), is investigated. O-IDTBR and EH-IDTBR form highly stable devices with all three polymers, whereas ITIC and ITIC-M devices suffer from burn-in losses and long-term degradation. Conformational instability is found to be responsible for the poor photostability of ITIC and ITIC-M, resulting in poor device stability. Twisting and potential breakage of the chemical bond that links the end group to the main backbone of ITIC and ITIC-M molecules causes undesirable conformational changes. Potential strategies to overcome such detrimental photo-induced conformational changes in NFAs are proposed.
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| 3. |
- Davies, Katherine Rebecca, et al.
(författare)
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Photoelectrocatalytic Surfactant Pollutant Degradation and Simultaneous Green Hydrogen Generation
- 2023
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Ingår i: Industrial & Engineering Chemistry Research. - 1520-5045 .- 0888-5885. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, we demonstrate a photoelectrocatalysistechniquefor simultaneous surfactant pollutant degradation and green hydrogengeneration using mesoporous WO3/BiVO4 photoanodeunder simulated sunlight irradiation. The materials properties suchas morphology, crystallite structure, chemical environment, opticalabsorbance, and bandgap energy of the WO3/BiVO4 films are examined and discussed. We have tested the anionic type(sodium 2-naphthalenesulfonate (S2NS)) and cationic type surfactants(benzyl alkyl dimethylammonium compounds (BAC-C12)) as model pollutants.A complete removal of S2NS and BAC-C12 surfactants at 60 and 90 min,respectively, by applying 1.75 V applied potential vs RHE to the circuit,under 1 sun was achieved. An interesting competitive phenomenon forphotohole utilization was observed between surfactants and adsorbedwater. This led to the formation of H2O2 fromwater alongside surfactant degradation (anode) and hydrogen evolution(cathode). No byproducts were observed after the direct photoholemediated degradation of surfactants, implying its advantage over otherAOPs and biological processes. In the cathode compartment, 82.51 mu mol/cm(2) and 71.81 mu mol/cm(2) of hydrogen gas weregenerated during the BAC-C12 and S2NS surfactant degradation process,respectively, at 1.75 V RHE applied potential.
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| 4. |
- Davies, Katherine Rebecca, et al.
(författare)
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Solar light-driven simultaneous pharmaceutical pollutant degradation and green hydrogen production using a mesoporous nanoscale WO 3 /BiVO 4 heterostructure photoanode
- 2023
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Ingår i: Journal of Environmental Chemical Engineering. - 2213-3437 .- 2213-2929. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectrocatalysis is one of the most favourable techniques that could be used in this remit as it has the potential to utilise natural sunlight to generate oxidants in situ to mediate effective pollutant degradation. This work, therefore, utilises a mesoporous nanoscale WO3/BiVO4 heterostructure photoanode to effectively degrade ibuprofen in wastewater combined with simultaneous green hydrogen generation at the cathode under simulated sunlight. A near complete degradation (>96%) of ibuprofen (starting concentration of 100 mg/L), with no hazardous intermediates (determined via mass spectrometry analysis), along with simultaneous H2 evolution of 114 µmol/cm2 after 145 min was demonstrated in this work. In addition, intermediate product analysis, the role of the type of in situ oxidants on degradation, the mechanistic pathway of degradation, and the material characteristics of mesoporous photoanode were also investigated. First experimental evidence of in situ generated H2O2 contributing to the degradation of ibuprofen is presented.
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| 5. |
- Jain, Sagar M., et al.
(författare)
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An effective approach of vapour assisted morphological tailoring for reducing metal defect sites in lead-free, (CH3NH3)(3)Bi2I9 bismuth-based perovskite solar cells for improved performance and long-term stability
- 2018
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Ingår i: Nano Energy. - : ELSEVIER SCIENCE BV. - 2211-2855 .- 2211-3282. ; 49, s. 614-624
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Tidskriftsartikel (refereegranskat)abstract
- We present a controlled, stepwise formation of methylammonium bismuth iodide (CH3NH3)(3)Bi2I9 perovskite films prepared via the vapour assisted solution process (VASP) by exposing BiI3 films to CH3NH3I (MAI) vapours for different reaction times, (CH3NH3)(3)Bi2I9 semiconductor films with tunable optoelectronic properties are obtained. Solar cells prepared on mesoporous TiO2 substrates yielded hysteresis-free efficiencies upto 3.17% with good reproducibility. The good performance is attributed mainly to the homogeneous surface coverage, improved stoichiometry, reduced metallic content in the bulk, and desired optoelectronic properties of the absorbing material. In addition, solar cells prepared using pure BiI3 films without MAI exposure achieved a power conversion efficiency of 0.34%. The non-encapsulated (CH3NH3)(3)Bi2I9 devices were found to be stable for as long as 60 days with only 0.1% drop in efficiency. This controlled formation of (CH3NH3)(3)Bi2I9 perovskite films highlights the benefit of the VASP technique to optimize material stoichiometry, morphology, solar cell performance, and long-term durability.
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| 6. |
- Nguyen, Ky V., et al.
(författare)
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The Effect of Direct Electron Beam Patterning on the Water Uptake and Ionic Conductivity of Nafion Thin Films
- 2023
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Ingår i: Advanced Electronic Materials. - 2199-160X. ; 9:8
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Tidskriftsartikel (refereegranskat)abstract
- The effect of electron-beam patterning on the water uptake and ionic conductivity of Nafion films using a combination of X-ray photoelectron spectroscopy, quartz crystal microbalance studies, neutron reflectometry, and impedance spectroscopy is reported. The aim is to further characterize the nanoscale patterned Nafion structures recently used as a key element in novel ion-to-electron transducers by Gluschke et al. To enable this, the electron beam patterning process is developed for large areas, achieving patterning speeds approaching 1 cm2 h−1, and patterned areas as large as 7 cm2 for the neutron reflectometry studies. It is ultimately shown that electron-beam patterning affects both the water uptake and the ionic conductivity, depending on film thickness. Type-II adsorption isotherm behavior is seen for all films. For thick films (≈230 nm), a strong reduction in water uptake with electron-beam patterning is found. In contrast, for thin films (≈30 nm), electron-beam patterning enhances water uptake. Notably, for either thickness, the reduction in ionic conductivity arising from electron-beam patterning is kept to less than an order of magnitude. Mechanisms are proposed for the observed behavior based on the known complex morphology of Nafion films to motivate future studies of electron-beam processed Nafion.
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