Dr Alan Dunbar
Department of Chemical and Biological Engineering
Senior Lecturer in Energy
REF Co-ordinator
a.dunbar@sheffield.ac.uk
+44 114 222 7551
+44 114 222 7551
Room G56, Sir Robert Hadfield Building
Full contact details
Dr Alan Dunbar
Department of Chemical and Biological Engineering
Room G56
Sir Robert Hadfield Building
Mappin Street
Sheffield
S1 3JD
Department of Chemical and Biological Engineering
Room G56
Sir Robert Hadfield Building
Mappin Street
Sheffield
S1 3JD
- Profile
-
I attained my MPhys in Physics with Electronics at UMIST (Manchester) in 1997, and my PhD entitled `Preparation and characterisation of Silicon – Germanium quantum dots´ in 2001 under the supervision of Dr M. Halsall. After my PhD, I moved to the University of Canterbury, Christchurch, New Zealand to work for two years with Associate Professor Simon Brown investigating the electrical properties of metallic nano-particles. I applied percolation theory to explain the onset of conduction in thin films of deposited nano-particles in conjunction with morphological data obtained by atomic force microscopy and electron microscopy.
I then returned to the UK to begin working in the University of Sheffield's Department of Physics and Astronomy where I developed gas sensors for volatile organic compounds with Dr T. Richardson. The porphyrin based gas sensors undergo strong colour changes upon exposure to specific toxic gases which co-ordinate to the porphyrin as axial ligands.
I then took up a research post working with Prof. R. Jones FRS and Prof D Lidzey focused on the optimization of polymer based solar cells through understanding how the nano-scale morphology of the thin polymer films wthin the devices influences the device efficiency. This involved in situ spectroscopic ellipsometry and x-ray reflectivity to investigate the development of phase separation during the deposition of the thin films of solar cell materials.
In 2009 I was appointed as lecturer in energy in the Department of Chemical Engineering and Biological at the University of Sheffield, and in 2010 I took on the role of first year tutor. In Jan 2014 I took on the role of Post Graduate Research Tutor, and then in Sept 2014 became Director of Student Support. In 2015 I was promoted to Senior Lecturer in Energy. I now lead an active and diverse research group studying various research interests.
- Research interests
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- Polymer Based Solar Cells
- Experimental techniques to characterise nano-scale phase separation in polymers
- Thin film toxic gas sensors
- Electrical properties of nano-structured systems
- Publications
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Journal articles
- Using Ag nanoparticles in the electron transport layer of perovskite solar cells to improve efficiency. Solar Energy, 268, 112318-112318.
- Corrigendum to ‘Deciphering perovskite decomposition in a humid atmosphere with TOF-GISANS’ [Energy Rep. 8 (Suppl. 11) (2022) 22–33]. Energy Reports, 9, 5224-5226.
- Influence of additives on the in situ crystallization dynamics of methyl ammonium lead halide perovskites. ACS Applied Energy Materials, 4(2), 1398-1409.
- Controlling PbI2 stoichiometry during synthesis to improve the performance of perovskite photovoltaics. Chemistry of Materials.
- Adhesion of grafted-to polyelectrolyte brushes functionalized with calix[4]resorcinarene and deposited as a monolayer. Langmuir, 36(46), 13843-13852. View this article in WRRO
- Interchain spacing and screening length modification of PSS backbone chains in zwitterion-doped poly(3,4-ethylenedioxythiophene):polystyrene sulfonate. Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques, 14(S1), S60-S68. View this article in WRRO
- Improved performance and stability of organic solar cells by the incorporation of a block copolymer interfacial layer. Advanced Materials Interfaces. View this article in WRRO
- Perovskite crystallization dynamics during spin-casting : an In situ wide-angle x-ray scattering study. ACS Applied Energy Materials, 3(7), 6155-6164. View this article in WRRO
- Low cost, high sensitivity detection of waterborne Al3+ cations and F− anions via the fluorescence response of a morin derivative dye. Analytica Chimica Acta, 1105, 1-10. View this article in WRRO
- Profile retrieval of a buried periodic structure using spin echo grazing incidence neutron scattering. Applied Physics Letters, 116(10). View this article in WRRO
- The electricity demand of an EV providing power via vehicle-to-home and its potential impact on the grid with different electricity price tariffs. Energy Reports, 6, 132-141. View this article in WRRO
- In−situ monitoring Poly(3-hexylthiophene) nanowire formation and shape evolution in solution via small angle neutron scattering. Solar Energy Materials and Solar Cells, 202. View this article in WRRO
- Interfacial width and phase equilibrium in polymer-fullerene thin-films. Communications Physics, 2(1). View this article in WRRO
- Adaptive and sensitive fibre-optic fluorimetric transducer for air- and water-borne analytes. Talanta, 199, 40-45. View this article in WRRO
- Enhancement of Dunaliella salina growth by using wavelength shifting dyes. Journal of Applied Phycology. View this article in WRRO
- Determination of the Thin Film Structure of Zwitterion Doped Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate). A Neutron Reflectivity Study.. ACS Applied Materials & Interfaces. View this article in WRRO
- Stoichiometry-dependent local instability in MAPbI3 perovskite materials and devices. Journal of Materials Chemistry A. View this article in WRRO
- Does 1,8-diiodooctane affect the aggregation state of PC71BM in solution?. Royal Society Open Science. View this article in WRRO
- Understanding the gas adsorption kinetics of Langmuir-Schaefer porphyrin films using two comparative sensing systems. Sensors and Actuators B: Chemical, 254, 669-680. View this article in WRRO
- Quantitative Analysis of the Molecular Dynamics of P3HT:PCBM Bulk Heterojunction. The Journal of Physical Chemistry B. View this article in WRRO
- An X-ray scattering and electron microscopy study of methylammonium bismuth perovskites for solar cell applications. Journal of Materials Research. View this article in WRRO
- Improved efficiency in organic solar cells via conjugated polyelectrolyte additive in the hole transporting layer. Journal of Materials Chemistry C, 4(45), 10722-10730. View this article in WRRO
- Monitoring the Formation of a CH₃NH₃PbI₃–⨯Cl⨯ Perovskite during Thermal Annealing Using X-Ray Scattering. Advanced Functional Materials, 26(27), 4934-4942. View this article in WRRO
- Controlling surface adsorption to enhance the selectivity of porphyrin based gas sensors. Applied Surface Science, 362, 191-201.
- Physical mechanisms responsible for the water-induced degradation of PC61
BM P3HT photovoltaic thin films. Journal of Polymer Science Part B: Polymer Physics, 54(2), 141-146. View this article in WRRO
- Minimising microbubble size through oscillation frequency control. Chemical Engineering Research and Design, 104, 357-366. View this article in WRRO
- Organic photovoltaic devices with enhanced efficiency processed from non-halogenated binary solvent blends. Organic Electronics, 21, 216-222. View this article in WRRO
- Vertical stratification and its impact on device performance in a polycarbazole based copolymer solar cells. Journal of Materials Chemistry C, 3(16), 4007-4015. View this article in WRRO
- Improving the selectivity of a free base tetraphenylporphyrin based gas sensor for NO2 and carboxylic acid vapors. Sensors and Actuators B: Chemical, 206, 74-83.
- A proto-type sensor for volatile organic compounds based on magnesium porphyrin molecular films. Sensors and Actuators, B: Chemical, 202, 854-860.
- Real time laser interference microscopy for bar-spread polystyrene/poly(methyl methacrylate) blends. Journal of Polymer Science Part B: Polymer Physics, n/a-n/a.
- Morphology Development in Amorphous Polymer: Fullerene Photovoltaic Blend Films During Solution Casting. Advanced Functional Materials. View this article in WRRO
- Direct observation of morphological development during the spin-coating of polystyrene-poly(methyl methacrylate) polymer blends. Journal of Polymer Science, Part B: Polymer Physics, 51(11), 875-881.
- Polymer Solar Cells: Fabricating High Performance, Donor-Acceptor Copolymer Solar Cells by Spray-Coating in Air (Adv. Energy Mater. 4/2013). Advanced Energy Materials, 3(4), 410-410.
- Fabricating high performance, donor-acceptor copolymer solar cells by spray-coating in air. Advanced Energy Materials, 3(4), 505-512.
- A neutron spin echo resolved grazing incidence scattering study of crystallites in organic photovoltaic thin films. Applied Physics Letters, 102(7).
- Competition between substrate-mediated π-π stacking and surface-mediated Tg depression in ultrathin conjugated polymer films. The European Physical Journal E, 35(12). View this article in WRRO
- Solar Cells: Correlating Structure with Function in Thermally Annealed PCDTBT:PC70BM Photovoltaic Blends (Adv. Funct. Mater. 7/2012). Advanced Functional Materials, 22(7), 1321-1321.
- Macroscopic expansion of tetraphenylporphyrin Langmuir layers stimulated by protonation. SOFT MATTER, 8(10), 2807-2811.
- Correlating structure with function in thermally annealed PCDTBT:PC
70 BM photovoltaic blends. Advanced Functional Materials, 22(7), 1399-1408.
- In situ imaging and height reconstruction of phase separation processes in polymer blends during spin coating.. ACS Nano, 5(6), 5124-5131.
- Nanoscale Morphology of a PCDTBT:PCBM Photovoltaic Blend.. Adv. Energy Mater., 1(4), 499-504.
- A Phase Diagram of the P3HT:PCBM Organic Photovoltaic System: Implications for Device Processing and Performance. MACROMOLECULES, 44(8), 2908-2917.
- Nanoscale Phase Separation of P3HT PCBM Thick Films As Measured by Small-Angle X-ray Scattering. MACROMOLECULES, 44(16), 6503-6508.
- Tuning free base tetraphenylporphyrins as optical sensing elements for volatile organic analytes. J MATER CHEM, 21(13), 4882-4887.
- Detection of volatile organic compounds using porphyrin derivatives.. J Phys Chem B, 114(36), 11697-11702.
- Macroscopic manifestation of a vapour-induced molecular switching phenomenon. SOFT MATTER, 6(14), 3157-3159.
- The development of nanoscale morphology in polymer: fullerene photovoltaic blends during solvent casting. SOFT MATTER, 6(17), 4128-4134.
- Depletion of PCBM at the cathode interface in P3HT/PCBM thin films as quantified via neutron reflectivity measurements.. Adv Mater, 22(22), 2444-2447.
- A solution concentration dependent transition from self-stratification to lateral phase separation in spin-cast PS:d-PMMA thin films.. Eur Phys J E Soft Matter, 31(4), 369-375. View this article in WRRO
- Alkylamine sensing using langmuir-blodgett films of n-alkyl-N-phenylamide-substituted zinc porphyrins.. J Phys Chem B, 112(36), 11278-11283.
- Langmuir-Schaefer films of five different free base tetraphenylporphyrins for optical-based gas sensing of NO2. SENSOR ACTUAT B-CHEM, 128(2), 468-481.
- Modeling the kinetics of gas adsorption in multilayer porphyrin films.. Langmuir, 23(4), 1759-1767.
- Experimental and simulational study of the operation conditions for a high transmission mass filter. Review of Scientific Instruments, 78(5).
- Investigation of free base, Mg, Sn, and Zn substituted porphyrin LB films as gas sensors for organic analytes.. J Phys Chem B, 110(33), 16646-16651.
- Morphological differences between Bi, Ag and Sb nano-particles and how they affect the percolation of current through nano-particle networks. European Physical Journal D, 39(3), 415-422.
- Construction and application of a UHV compatible cluster deposition system. Journal of Nanoparticle Research, 8(3-4), 405-416.
- Optical changes induced in Zn porphyrin solutions and LB films by exposure to amines. J PORPHYR PHTHALOCYA, 10(7), 978-985.
- Templated cluster assembly for production of metallic nanowires in passivated silicon V-grooves. Microelectronic Engineering, 73-74, 583-587.
- Formation of Electrically Conducting Mesoscale Wires Through Self-Assembly of Atomic Clusters. IEEE Transactions on Nanotechnology, 3(1 SPEC. ISS.), 61-66.
- Templated-assembly of conducting antimony cluster wires. Nanotechnology, 15(9), 1382-1387.
- Hole confinement and dynamics in δ-doped Ge quantum dots. Journal of Luminescence, 108(1-4), 329-332.
- Electrical measurements of nanoscale bismuth cluster films. European Physical Journal D, 24(1-3), 291-294.
- Strain seeding of Ge quantum dots grown on Si (001). Physica Status Solidi (B) Basic Research, 224(1), 257-260.
- Three-dimensional compositional analysis of quantum dots. Journal of Physics D: Applied Physics, 34(4), 636-644.
- The effect of strain field seeding on the epitaxial growth of Ge islands on Si(001). Applied Physics Letters, 78(12), 1658-1660.
- Structural, compositional and optical properties of self-organised Ge quantum dots. Physica Status Solidi (B) Basic Research, 224(1), 265-269.
- Studies of Compositional Variations in Germanium Quantum Dots Grown on Silicon. MRS Advances, 638, f14.5.1.
- Electron diffraction and Raman studies of the effect of substrate misorientation on ordering in the AlGaInP system. Journal of Applied Physics, 85(1), 199-202.
- Erbium photoluminescence in sol-gel derived titanium dioxide films. Proceedings of SPIE - The International Society for Optical Engineering, 3725, 239-242.
- Functionalized BODIPYs as Tailor‐Made and Universal Interlayers for Efficient and Stable Organic and Perovskite Solar Cells. Advanced Materials Interfaces, 2102324-2102324.
- Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials. Journal of Visualized Experiments(83).
- Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials. Journal of Visualized Experiments(83).
- Efficient planar heterojunction mixed-halide perovskite solar cells deposited via spray-deposition. Energy and Environmental Science, 7(9), 2944-2950.
- Low-Cost, High-Sensitivity Detection of Waterborne Al3+ Cations and F− Anions via the Fluorescence Response of a Morin Derivative Dye. Engineering Proceedings, 6(1), 29-29.
Conference proceedings papers
- An introduction to perovskites for solar cells and their characterisation. Energy Reports, Vol. 8(11) (pp 89-106). Sheffield, UK, 5 April 2022 - 6 April 2022.
- Exploring the possibility to provide black start services by using vehicle-to-grid. Energy Reports, Vol. 8(11) (pp 74-82), 5 April 2022 - 6 April 2022.
- Deciphering perovskite decomposition in a humid atmosphere with TOF-GISANS. Energy Reports, Vol. 8(Suppl_11) (pp 23-33). Sheffield, UK, 5 April 2022 - 6 April 2022.
- The importance of lead iodide stoichiometry when preparing perovskite solar cells. Proceedings of the International Conference on Hybrid and Organic Photovoltaics
- Zinc chloride as a performance-enhancing additive for MAPbI3 solar cells produced in air.. Proceedings of the International Conference on Hybrid and Organic Photovoltaics
- Machine learning approach for electric vehicle availability forecast to provide vehicle-to-home services. Energy Reports, Vol. 7(Suppl 2) (pp 71-80). Virtual conference, 12 January 2021 - 13 January 2021.
- Fabrication and characterization of hybrid photovoltaic devices based on N-type GaAs and polymer composites. Proceedings of the 2nd International Conference of Energy Harvesting, Storage, and Transfer (EHST'18) (pp 116-1-116-10). Niagara Falls, Canada, 7 June 2018 - 9 June 2018. View this article in WRRO
- Understanding the interactions of porphryin LB films with NO2. COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol. 284 (pp 339-344)
- Characterisation of the reaction of free-base porphyrin to nitrogen dioxide. COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol. 284 (pp 345-349)
- Assembly of bismuth clusters into nanowires using etched V-grooves as templates. Conference on Optoelectronic and Microelectronic Materials and Devices, Proceedings, COMMAD (pp 327-330)
- Measurement of the Conductivity Exponent in Random Percolating Networks of Nanoscale Bismuth Clusters.. ICMENS (pp 350-356)
- Formation of electrically conducting mesoscale wires through self-assembly of atomic clusters. Proceedings of SPIE - The International Society for Optical Engineering, Vol. 5118 (pp 411-420)
- Formation of Nanowires at the Percolation Threshold in Rectangular 2D Systems. Proceedings of SPIE - The International Society for Optical Engineering, Vol. 5055 (pp 189-203)
- Studies of compositional variations in germanium quantum dots grown on silicon. Materials Research Society Symposium - Proceedings, Vol. 638 (pp F1451-F1456)
- Investigations of ordering in AlGaInP. MICROSCOPY OF SEMICONDUCTING MATERIALS 1997(157) (pp 257-260)
- In-situ characterization of metal halide perovskite formation in environmentally friendly solvents using in situ wide and small angle X-ray scattering. Proceedings of the MATSUS Fall 2023 Conference, 16 October 2023 - 20 October 2023.
- Using Ag nanoparticles in the electron transport layer of perovskite solar cells to improve efficiency. Solar Energy, 268, 112318-112318.
- Teaching activities
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- CPE430/ CPE6000 Low Carbon Energy, Science and Technology
- CPE1002 Chemical Engineering Design (Chemical Process Principles 1)
- CPE101/110