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158 results on '"Holliman, Peter J."'

3. A facile method to obtain colloidal dispersions of nickel hydroxide: improving the processing of nickel oxide and facilitating its upscaling for perovskite-type solar devices.

Author

Valls, Rafael Martí, primary, Rodríguez, Rodrigo García, additional, Rojas, Diana Meza, additional, Dunlop, Tom, additional, Jones, Eurig, additional, Thomas, Suzanne K., additional, Davies, Matthew L., additional, Holliman, Peter J., additional, Baker, Jenny, additional, and Charbonneau, Cecile, additional

Published
2024
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11. Synthesis of SOT-OH and its application as a building block for the synthesis of new dimeric and trimeric Spiro-OMeTAD materials

Author

Cariello, Michele, Pant, Namrata, Harkiss, Alexander H., Tracey, Frances M., Cameron, Joseph, Skabara, Peter J., Holliman, Peter J., Docampo, Pablo, and Cooke, Graeme

Abstract

Spiro-OMeTAD has become a ubiquitous hole-transporting material (HTM) in perovskite-based solar cells. However, it has several intrinsic drawbacks including its long-term stability, low conductivity and hole-mobility. Hence, the synthesis of new derivatives with improved charge transporting properties remains an important goal. Here, we have devised a novel synthetic route to prepare unsymmetrically functionalised Spiro-OMeTAD derivatives. We report the synthesis of a mono-demethylated Spiro-OMeTAD derivative, SOT-OH, utilising two different synthetic protocols and show two new derivatives, a dimer (SOT-D) and a trimer (SOT-T) as exemplars. We fully characterise the developed materials and show significantly higher conductivity values than Spiro-OMeTAD when doped with standard ionic salts at the same concentrations. The solar cells fabricated using the mixed composition Cs0.05(FA0.85MA0.15)0.95PbI3 perovskite and the novel SOT-D show power conversion efficiencies of up to 16.4% under standard AM1.5 illumination compared to 16.1% observed when using the benchmark Spiro-OMeTAD.

Published
2022

13. Adsorption of phosphate by halloysite (7 angstrom) nanotubes (HNTs)

Author

Gray-Wannell, Nia, Holliman, Peter J., Greenwell, H. Christopher, Delbos, Evelyne, Hillier, Stephen, and Olsson, Anders

Subjects
Materials Chemistry
Abstract

The adsorption and retention of phosphates in soil systems is of wide environmental importance, and understanding the surface chemistry of halloysite (a common soil clay mineral) is also of prime importance in many emerging technological applications of halloysite nanotubes (HNTs). The adsorption of phosphate anions on tubular halloysite (7 angstrom) has been studied to gain a greater understanding of the mechanism and kinetics of adsorption on the surface of HNTs. Two well-characterized tubular halloysites with differing morphologies have been studied: one polygonal prismatic and one cylindrical, where the cylindrical form has a greater surface area and shorter tube length. Greater phosphate adsorption of up to 42 mu mol g(-1) is observed on the cylindrical halloysite when compared to the polygonal prismatic sample, where adsorption reached a maximum of just 15 mu mol g(-1) compared to a value for platy kaolinite (KGa-2) of 8 mu mol g(-1). Phosphate adsorption shows strong pH dependence, and the differences in phosphate sorption between the prismatic and cylindrical morphologies suggest that phosphate absorption does not occur at the same pH-dependent alumina edge sites and that the lumen may have a greater influence on uptake for the cylindrical form.

Published
2020

23. Novel benzothiazole half-squaraines: model chromophores to study dye–TiO2interactions in dye-sensitized solar cells

Author

Holliman, Peter J., primary, Kershaw, Christopher P., additional, Jones, Eurig W., additional, Meza-Rojas, Diana, additional, Lewis, Anthony, additional, McGettrick, James, additional, Geatches, Dawn, additional, Sen, Kakali, additional, Metz, Sebastian, additional, Tizzard, Graham J., additional, and Coles, Simon J., additional

Published
2020
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24. Low cost triazatruxene hole transporting material for >20% efficient perovskite solar cells

Author

Connell, Arthur, Wnag, Zhiping, Lin, Yen-Hung, Greenwood, Peter C., Wiles, Alan A., Jones, Eurig W., Furnell, Leo, Anthony, Rosie, Kershaw, Christopher P., Cooke, Graeme, Snaith, Henry J., and Holliman, Peter J.

Abstract

Organic hole-transporting materials (HTM) have shown excellent ability in achieving high efficiency perovskite solar cells. However, their high cost significantly limits their applications in scaling-up perovskite solar cells. Here, we report an efficient, low-cost HTM, called TAT-tBuSty, comprising a central triazatruxene moiety with 3 terminal tert-butoxy styrene groups and 3 hexyl side chains on the indole nitrogen. For the first time, we use an inexpensive liquid precur-sor to attach the donor ligand to the molecule. This enables purification of the HTM using a silica plug and recrystallization without the need for complicated column chromatography, which is typically required to purify solid-precursor-prepared HTMs. We estimate that the cost for the purified TAT-tBuSty is $69.90 g-1, which is 35% cheaper than the widely-used 2,2′7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD; ca. $112.05 g-1). Using this low-cost TAT-tBuSty as the HTM in a caesium-formamidinium mixed-cation perovskite solar cell, we have successfully achieved a champion power conversion efficiency (PCE) of 20.3% (19.4% stabilized efficiency), which is comparable to the efficiency of devices using the reference spiro-OMeTAD HTM. Our work is crucial for up-scaling of next-generation high-performance metal-halide perovskite solar cells.

Published
2019

27. Novel benzothiazole half-squaraines: model chromophores to study dye–TiO2 interactions in dye-sensitized solar cells.

Author

Holliman, Peter J., Kershaw, Christopher P., Jones, Eurig W., Meza-Rojas, Diana, Lewis, Anthony, McGettrick, James, Geatches, Dawn, Sen, Kakali, Metz, Sebastian, Tizzard, Graham J., and Coles, Simon J.

Abstract

We report the synthesis of 9 new half squaraine (HfSQ) dyes; 5 containing a benzothiazole moiety and 4 containing an indolenine moiety. X-ray single crystal structural and characterisation data have been correlated with device data to understand the widely reported but poorly understood influence of S heteroatoms on DSC device performance. The S heteroatom in these new dyes has also been used as an atomic probe of the dye–TiO2 interface to dye binding and orientation. Thus, for the first time, using the S heteroatom probe, angle-resolved X-ray photoelectron (AR-XPS) data have shown these dyes sit horizontally at the dye–TiO2 interface confirmed by DFT computer modelling of novel and analogous HfSQ dyes with a benzoindole backbone. [ABSTRACT FROM AUTHOR]

Published
2020
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31. Low cost triazatruxene hole transporting material for ＞20% efficiency perovskite solar cells.

Author

Connell, Arthur, Wang, Zhiping, Lin, Yen-Hung, Greenwood, Peter C., Wiles, Alan A., Jones, Eurig W., Furnell, Leo, Anthony, Rosie, Kershaw, Christopher P., Cooke, Graeme, Snaith, Henry J., and Holliman, Peter J.

Abstract

Organic hole-transporting materials (HTM) have shown excellent ability in achieving high efficiency perovskite solar cells. However, their high cost significantly limits their applications in scaling-up perovskite solar cells. Here, we report an efficient, low-cost HTM, called TAT-tBuSty, comprising a central triazatruxene moiety with 3 terminal tert-butoxy styrene groups and 3 hexyl side chains on the indole nitrogen. For the first time, we use an inexpensive liquid precursor to attach the donor ligand to the molecule. This enables purification of the HTM using a silica plug and recrystallization without the need for complicated column chromatography, which is typically required to purify solid-precursor-prepared HTMs. We estimate that the cost for the purified TAT-tBuSty is $69.90 g−1, which is 35% cheaper than the widely-used 2,2′7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD; ca. $112.05 g−1). Using this low-cost TAT-tBuSty as the HTM in a caesium-formamidinium mixed-cation perovskite solar cell, we have successfully achieved a champion power conversion efficiency (PCE) of 20.3% (19.4% stabilized efficiency), which is comparable to the efficiency of devices using the reference spiro-OMeTAD HTM. Our work is crucial for up-scaling of next-generation high-performance metal-halide perovskite solar cells. [ABSTRACT FROM AUTHOR]

Published
2019
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32. Improving the light harvesting and colour range of methyl ammonium lead tri-bromide (MAPbBr3) perovskite solar cells through co-sensitisation with organic dyes.

Author

McFarlane, Tamara D., De Castro, Catherine S., Holliman, Peter J., and Davies, Matthew L.

Subjects
METHYLAMMONIUM, PEROVSKITE, SOLAR cells
Abstract

Co-sensitisation of methylammonium lead tri-bromide perovskite solar cells with red (D205) and blue (SQ2) organic dyes improves device efficiencies and allows device colour tuning. Sensitising the film after perovskite crystallisation produces higher device efficiencies (2.6% SQ2, 3.1% D205) than perovskite-only devices (2%) and devices sensitised before the perovskite layer deposition (1.5% SQ2, 2.0% D205). [ABSTRACT FROM AUTHOR]

Published
2019
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47. Influence of Water Table Depthon Pore Water Chemistry and Trihalomethane Formation Potential in Peatlands.

Author

Gough, Rachel, Holliman, Peter J., Fenner, Nathalie, Peacock, Mike, and Freeman, Christopher

Subjects
*CARBON compounds, *WATERSHEDS, *PEATLANDS, *WATER purification, *TRIHALOMETHANES
Abstract

Drained peatland catchments are reported to produce more colored, dissolved organic carbon (DOC)-rich water, presenting problems for potable water treatment. The blocking of peatland drainage ditches to restore the water table is increasingly being considered as a strategy to address this deterioration in water quality. However, the effect of ditch blocking on the potential of DOC to form trihalomethanes (THMs) has not been assessed. In this study, the effect of peat rewetting on pore water DOC concentration and characteristics (including THM formation potential [THMFP]) was assessed over 12 months using peat cores collected from two drained peatland sites. The data show little evidence of differences in DOC concentration or characteristics between the different treatments. The absence of any difference in the THMFP of pore water between treatments suggests that, in the short term at least, ditch blocking may not have an effect on the THMFP of waters draining peatland catchments. [ABSTRACT FROM AUTHOR]

Published
2016
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48. Solvent issues during processing and device lifetime for perovskite solar cells.

Author

Holliman, Peter J., Jones, Eurig W., Connell, Arthur, Ghosh, Sanjay, Furnell, Leo, and Hobbs, Robert J.

Subjects
PHOTOVOLTAIC power generation, SOLVENTS, SOLAR cells, PEROVSKITE, MANUFACTURED products, ETHANES
Abstract

This paper considers the manufacturing issues associated with dimethyl formamide, γ-butyrolactone, dimethyl sulfoxide and chlorobenzene solvents, in particular the health and safety issues of using these solvents in scaled perovskite photovoltaic processing. Issues of device lifetime are also considered, for example the effects of atmospheric conditions (e.g. humidity). [ABSTRACT FROM AUTHOR]

Published
2015
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50. Ultra-fast co-sensitization and tri-sensitization of dye-sensitized solar cells with N719, SQ1 and triarylamine dyes

Author

Holliman, Peter J., primary, Mohsen, Moneer, additional, Connell, Arthur, additional, Davies, Matthew L., additional, Al-Salihi, Kareem, additional, Pitak, Mateusz B., additional, Tizzard, Graham J., additional, Coles, Simon J., additional, Harrington, Ross W., additional, Clegg, William, additional, Serpa, Carlos, additional, Fontes, Octávio H., additional, Charbonneau, Cecile, additional, and Carnie, Matthew J., additional

Published
2012
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