Professor Paul Sellin
Professor, Head of Department
Qualifications: B.Sc. (Birmingham), PhD (Edinburgh), MInstP, CPhys, MIEEE
Email: p.sellin@surrey.ac.uk
Phone: Work: 01483 68 6814
Room no: 07 BB 03
Further information
Biography
- BSc Physics (Hons.) First Class, University of Birmingham, Sept 1985 - July 1988
- PhD in Experimental Nuclear Physics. University of Edinburgh, Thesis entitled ‘Proton radioactivity measurements using a double-sided silicon strip detector’, Oct 1988 - Jan 1992
Research Interests
- Development and characterisation of high-Z compound semiconductor materials (eg. GaAs, InP, CdTe, CdZnTe) for X-ray and nuclear medicine imaging detectors.
- Characterisation of radiation-hard detector materials (eg. diamond, silicon carbide, gallium nitride) for specialised radiation imaging applications, where high dose rate and/or high temperature capability is required.
- New semiconductor detector materials suitable for low temperature processing of direct X-ray conversion layers, compatible with CMOS pixel devices.
- New technologies for neutron detection, including boron-loaded liquid scintillators and boron/lithium-coated semiconductor devices.
Recent student PhD theses
"X-Ray Beam Studies of Charge Sharing in Small Pixel, Spectroscopic, CdZnTe Detector"
Chris Allwork, 2013
Abstract
“Electric field studies on Cadmium Zinc Telluride Materials”
Georgios Prekas, 2011
Abstract
“Fabrication and Characterisation of Graphite Electrodes for Diamond X-ray Dosimeters”
Hussain Albarakaty, 2011
Abstract
"Properties of CdMnTe as a room temperature semiconductor radiation detector"
James Parkin, 2009
Abstract
"Charge Transport and Low Temperature Phenomena in Single Crystal CdZnTe"
Matthew Veale, 2009
Abstract
"Charge Carrier Transport in THM grown CdTe"
Andrew Davies, 2008
Abstract
"Digital Data Acquisition Techniques for Fast Neutron Detection using Liquid Scintillator"
Ghulam Jaffar, 2007
Abstract
"Temperature dependent charge transport studies in polycrystalline and single crystal CVD diamond detectors"
Annika Lohstroh, 2006
Abstract
"Characterisation of Semi-Insulating GaAs and InP for use in Radiation Detection"
Hanan El-Abbassi, 2004
Abstract
"Development of CVD Diamond Radiation Detectors"
Arnaldo Galbiati, 2003
Abstract
"Development of a Capture-Gated Fast Neutron Detector with Pulse Shape Discrimination using Digital Pulse Processing"
Saddig Jastaniah, 2003
Abstract
Please contact me if you wish to receive a complete copy of one of these theses.
Selected Research Talks:
ICNMTA2006 - Singapore July 10-14th 2006
"IBIC studies of charge transport in single-crystal synthetic diamond"
PDF file (3758 kB)
IWORID7 - Grenoble July 3-7th 2005
"Recent developments in compound semiconductor radiation imaging detectors"
PDF file (4783 kB)
IEEE NSS / RTSD - Rome October 16-22nd 2004
"Charge transport and mobility mapping in CdTe"
PDF file (2926 kB)
9th International Conference on Nuclear Microprobe Technology and Applications - Dubrovnik September 13-17th 2004
"Mobility and lifetime mapping in wide bandgap semiconductors using digital IBIC"
PDF file (2360 kB)
IEEE NSS / RTSD - Portland October 20-24th 2003
"The role of defects on CdTe detector performance"
PDF file (2071 kB)
"Digital capture-gated neutron detection and pulse shape discrimination in liquid scintillators"
PDF file (740 kB)
Research Collaborations
A member of the Basic Technology HEXITEC CdZnTe detector research collaboration (www.hexitec.co.uk).
Further details can be found on my personal web page.
Publications
Highlights
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(2011) 'High charge-carrier mobilities in blends of poly(triarylamine) and TIPS-pentacene leading to better performing X-ray sensors'. Elsevier Organic Electronics, 12 (11), pp. 1903-1908.Full text is available at: http://epubs.surrey.ac.uk/7284/
Abstract
A new class of X-ray sensor – in which there is a blend of poly(triarylamine) (PTAA) and 6,13-bis(triisopropylsilylethynyl) (TIPS)-pentacene in the active layer of a diode structure – has been developed. The crystalline pentacene provides a fast route for charge carriers and leads to enhanced performance of the sensor. The first time-of-flight charge-carrier mobility measurement of this blend is reported. The mobility of PTAA and TIPS-pentacene in a 1:25 molar ratio was found to be 2.2 × 10−5 cm2 V−1 s−1 (averaged for field strengths between 3 × 104 and 4 × 105 V cm−1), which is about 17 times higher than that obtained in PTAA over the same range of field strengths. This higher mobility is correlated with a fourfold increase in the X-ray detection sensitivity in the PTAA:TIPS-pentacene devices.
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(2011) 'Radiation induced control of electric field in Au/CdTe/In structures'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 98 (23) Article number ARTN 232115 doi: 10.1063/1.3598414Full text is available at: http://epubs.surrey.ac.uk/130029/
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(2010) 'Achieving a Stable Time Response in Polymeric Radiation Sensors under Charge Injection by X-rays'. AMER CHEMICAL SOC ACS APPLIED MATERIALS & INTERFACES, 2 (6), pp. 1692-1699.doi: 10.1021/am100220yFull text is available at: http://epubs.surrey.ac.uk/2962/
- .
(2010) 'Electric field distributions in CdZnTe due to reduced temperature and x-ray irradiation'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 96 (13) Article number ARTN 133509 doi: 10.1063/1.3373526Full text is available at: http://epubs.surrey.ac.uk/5161/
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(2009) 'Characterization of thick film poly(triarylamine) semiconductor diodes for direct x-ray detection'. AMER INST PHYSICS JOURNAL OF APPLIED PHYSICS, 106 (6) Article number ARTN 064513 doi: 10.1063/1.3225909Full text is available at: http://epubs.surrey.ac.uk/712273/
Journal articles
- . (2013) 'An XPS study of bromine in methanol etching and hydrogen peroxide passivation treatments for cadmium zinc telluride radiation detectors'. Applied Surface Science, 264, pp. 681-686.
- . (2012) 'A study of timing properties of Silicon Photomultipliers'. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 695, pp. 257-260.
- . (2012) 'GaN detector development for particle and X-ray detection'. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 695, pp. 303-305.
- . (2012) 'Growth by the Multi-tube Physical Vapour Transport method and characterisation of bulk (Cd,Zn)Te'. Elsevier Journal of Crystal Growth, 352 (1), pp. 120-123.
- . (2012) 'A CdTe detector for hyperspectral SPECT imaging'. Journal of Instrumentation, 7 (8)
- . (2012) 'Growth by the Multi-tube Physical Vapour Transport method and characterisation of bulk (Cd,Zn)Te'. Journal of Crystal Growth, 352 (1), pp. 120-123.
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(2012) 'Development of large area polycrystalline diamond detectors for fast timing application of high-energy heavy-ion beams'. Institute of Physics Journal of Instrumentation, 7 (5) Article number P05005 Full text is available at: http://epubs.surrey.ac.uk/712259/
Abstract
We have studied the effects of electrode fabrication and detector capacitance on the time resolution of large area electronic grade polycrystalline chemical vapour deposited diamond sensors that are suitable for time of flight measurements of heavy ions at relativistic velocities. Sensors were prepared both in house, with Al or Au metal contacts, and commercially fabricated with Au/diamond-like carbon contacts. He, Ar and a mixture of Ne and O beams at 16.3, 33.5 and 21-23 MeV/u, respectively were used on these devices whilst arranged in transmission geometry. Signal processing only began over one meter away from the sensors. The present approach, where we have large-area/large capacitance multi-strip detectors with processing electronics at some distance from the target, is compatible with anticipated space limitations in particle- identification and tracking setups at existing and planned nuclear fragmentation facilities. In a systematic study under these conditions, we demonstrate that the time resolution is limited by detector capacitance and energy deposition in the sensors. An intrinsic time resolution σ = (44±5) ps was achieved for a diamond detector of ∼ 14 pF capacitance. We conclude that, once further refinements are made, a large area time of flight detection system using polycrystalline diamond detectors would be able to provide time resolutions better than 40 ps, approaching the requirement for particle-identification in relativistic fragmentation experiments, such as those at the facility for antiproton and ion research, FAIR. © 2012 IOP Publishing Ltd and Sissa Medialab srl.
- . (2012) 'X-ray beam studies of charge sharing in small pixel, spectroscopic, CdZnTe detectors'. IEEE Transactions on Nuclear Science, 59 (4 PART 3), pp. 1563-1568.
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(2012) 'Investigation of Te inclusion induced glides and the corresponding dislocations in CdZnTe crystal'. CRYSTENGCOMM, 14 (2), pp. 417-420.doi: 10.1039/c1ce05843f
- . (2012) 'Digital pulse height correction in HgI 2 γ-ray detectors'. Elsevier Journal of Instrumentation, 7 (4) Article number T04002
- . (2012) 'Study on electric field in Au/CdZnTe/In detectors under high fluxes of X-ray and laser irradiation'. IOP PUBLISHING LTD JOURNAL OF INSTRUMENTATION, 7 Article number ARTN P02011
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(2012) 'Heavy metallic oxide nanoparticles for enhanced sensitivity in semiconducting polymer x-ray detectors'. IOP Publishing Nanotechnology, 23 (23) Article number 235502 Full text is available at: http://epubs.surrey.ac.uk/605295/
Abstract
Semiconducting polymers have previously been used as the transduction material in x-ray dosimeters, but these devices have a rather low detection sensitivity because of the low x-ray attenuation efficiency of the organic active layer. Here, we demonstrate a way to overcome this limitation through the introduction of high density nanoparticles having a high atomic number (Z) to increase the x-ray attenuation. Specifically, bismuth oxide (Bi O ) nanoparticles (Z=83 for Bi) are added to a poly(triarylamine) (PTAA) semiconducting polymer in the active layer of an x-ray detector. Scanning electron microscopy (SEM) reveals that the Bi O nanoparticles are reasonably distributed in the PTAA active layer. The reverse bias dc currentvoltage characteristics for PTAABi O diodes (with indium tin oxide (ITO) and Al contacts) have similar leakage currents to ITO/PTAA/Al diodes. Upon irradiation with 17.5keV x-ray beams, a PTAA device containing 60wt% Bi O nanoparticles demonstrates a sensitivity increase of approximately 2.5 times compared to the plain PTAA sensor. These results indicate that the addition of high-Z nanoparticles improves the performance of the dosimeters by increasing the x-ray stopping power of the active volume of the diode. Because the Bi O has a high density, it can be used very efficiently, achieving a high weight fraction with a low volume fraction of nanoparticles. The mechanical flexibility of the polymer is not sacrificed when the inorganic nanoparticles are incorporated. © 2012 IOP Publishing Ltd.
- . (2012) 'An XPS study of bromine in methanol etching and hydrogen peroxide passivation treatments for cadmium zinc telluride radiation detectors'. Applied Surface Science,
- .
(2011) 'High charge-carrier mobilities in blends of poly(triarylamine) and TIPS-pentacene leading to better performing X-ray sensors'. Elsevier Organic Electronics, 12 (11), pp. 1903-1908.Full text is available at: http://epubs.surrey.ac.uk/7284/
Abstract
A new class of X-ray sensor – in which there is a blend of poly(triarylamine) (PTAA) and 6,13-bis(triisopropylsilylethynyl) (TIPS)-pentacene in the active layer of a diode structure – has been developed. The crystalline pentacene provides a fast route for charge carriers and leads to enhanced performance of the sensor. The first time-of-flight charge-carrier mobility measurement of this blend is reported. The mobility of PTAA and TIPS-pentacene in a 1:25 molar ratio was found to be 2.2 × 10−5 cm2 V−1 s−1 (averaged for field strengths between 3 × 104 and 4 × 105 V cm−1), which is about 17 times higher than that obtained in PTAA over the same range of field strengths. This higher mobility is correlated with a fourfold increase in the X-ray detection sensitivity in the PTAA:TIPS-pentacene devices.
- .
(2011) 'Radiation induced control of electric field in Au/CdTe/In structures'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 98 (23) Article number ARTN 232115 doi: 10.1063/1.3598414Full text is available at: http://epubs.surrey.ac.uk/130029/
- .
(2011) 'Locking carbon nanotubes in confined lattice geometries--a route to low percolation in conducting composites.'. J Phys Chem B, United States: 115 (20), pp. 6395-6400.doi: 10.1021/jp111998p
- . (2011) 'Morphology evolution of micron-scale secondary phases in CdZnTe crystals grown by vertical Bridgman method'. Elsevier Journal of Alloys and Compounds, 509 (5), pp. 2338-2342.
- . (2011) 'Pixellated Cd(Zn)Te high-energy X-ray instrument'. Journal of Instrumentation, 6 Article number C12009
- . (2011) 'An ASIC for the Study of Charge Sharing Effects in Small Pixel CdZnTe X-Ray Detectors'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 58 (5), pp. 2357-2362.
- . (2011) 'GaN detector development for particle and X-ray detection'. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
- .
(2011) 'A study of timing properties of Silicon Photomultipliers'. Elsevier Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Full text is available at: http://epubs.surrey.ac.uk/63080/
Abstract
Silicon Photomultipliers (SiPM) are solid-state pixelated photodetectors. Lately these sensors have been investigated for Time of Flight Positron Emission Tomography (ToF-PET) applications, where very good coincidence time resolution of the order of hundreds of picoseconds imply spatial resolution of the order of cm in the image reconstruction. The very fast rise time typical of the avalanche discharge improves the time resolution, but can be limited by the readout electronics and the technology used to construct the device. In this work the parameters of the equivalent circuit of the device that directly affect the pulse shape, namely the quenching resistance and capacitance and the diode and parasitic capacitances, were calculated. The mean rise time obtained with different preamplifiers was also measured.
- . (2011) 'The effect of annealing on the X-ray induced photocurrent characteristics of CVD diamond radiation detectors with different electrical contacts'. PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 208 (9), pp. 2079-2086.
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(2010) 'The effect of fast neutron irradiation on the performance of synthetic single crystal diamond particle detectors'. ELSEVIER SCIENCE SA DIAMOND AND RELATED MATERIALS, Athens, GREECE: 19 (7-9), pp. 841-845.Full text is available at: http://epubs.surrey.ac.uk/7672/
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(2010) 'Achieving a Stable Time Response in Polymeric Radiation Sensors under Charge Injection by X-rays'. AMER CHEMICAL SOC ACS APPLIED MATERIALS & INTERFACES, 2 (6), pp. 1692-1699.doi: 10.1021/am100220yFull text is available at: http://epubs.surrey.ac.uk/2962/
- .
(2010) 'Electric field distributions in CdZnTe due to reduced temperature and x-ray irradiation'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 96 (13) Article number ARTN 133509 doi: 10.1063/1.3373526Full text is available at: http://epubs.surrey.ac.uk/5161/
- . (2010) 'Investigation of the internal electric field distribution under in situ x-ray irradiation and under low temperature conditions by the means of the Pockels effect'. IOP PUBLISHING LTD JOURNAL OF PHYSICS D-APPLIED PHYSICS, 43 (8) Article number ARTN 085102
- . (2010) 'Influence of Contacts on Electric Field in an Au/(CdZn)Te/Au Detector: A Simulation'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 57 (4), pp. 2349-2358.
- . (2010) 'X-ray photoelectron study of high-energy He+ implanted a-SiC:H thin films'. Journal of Physics: Conference Series, 253 (1)
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(2010) 'Chemical etching and surface oxidation studies of cadmium zinc telluride radiation detectors'. WILEY-BLACKWELL SURFACE AND INTERFACE ANALYSIS, Antalya, TURKEY: 42 (6-7), pp. 795-798.doi: 10.1002/sia.3146
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(2010) 'Time walk correction of CdTe detectors using depth sensing technique'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 621 (1-3), pp. 506-512.Full text is available at: http://epubs.surrey.ac.uk/7514/
- . (2010) 'Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space Sublimation Method'. JAPAN SOC APPLIED PHYSICS JAPANESE JOURNAL OF APPLIED PHYSICS, 49 (2) Article number UNSP 025504
- . (2009) 'Low temperature time of flight mobility measurements on synthetic single crystal diamond'. ELSEVIER SCIENCE SA DIAMOND AND RELATED MATERIALS, 18 (11), pp. 1338-1342.
- . (2009) 'Characterization of CdZnTe Crystals Grown Using a Seeded Modified Vertical Bridgman Method'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 56 (5), pp. 2808-2813.
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(2009) 'Characterization of thick film poly(triarylamine) semiconductor diodes for direct x-ray detection'. AMER INST PHYSICS JOURNAL OF APPLIED PHYSICS, 106 (6) Article number ARTN 064513 doi: 10.1063/1.3225909Full text is available at: http://epubs.surrey.ac.uk/712273/
- . (2009) 'Conference Comments by the Editors'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 56 (3), pp. 724-724.
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(2009) 'Comparison of the x-ray spectroscopy response and charge transport properties of semi-insulating In/Al doped CdZnTe crystals'. AMER INST PHYSICS JOURNAL OF APPLIED PHYSICS, 105 (8) Article number ARTN 083101 doi: 10.1063/1.3097301Full text is available at: http://epubs.surrey.ac.uk/102451/
- . (2009) 'Study on temperature dependent resistivity of indium-doped cadmium zinc telluride'. IOP PUBLISHING LTD JOURNAL OF PHYSICS D-APPLIED PHYSICS, 42 (3) Article number ARTN 035105
- . (2009) 'Carbon Nanotube Based DNA Biosensor for Rapid Detection of Anti-Cancer Drug of Cyclophosphamide'. CURRENT NANOSCIENCE, 5 (3), pp. 312-317.
- . (2009) 'Charge transport performance of high resistivity CdZnTe crystals doped with In/Al'. Journal of Semiconductors, 30 (8) Article number 082002
- . (2009) 'Editorial conference comments by the editors'. IEEE IEEE Transactions on Nuclear Science, 56 (3), pp. 1034-1034.
- . (2009) 'A study on the low energy X/γ-ray spectral response of CdZnTe planar detectors'. Guangxue Xuebao/Acta Optica Sinica, 29 (11), pp. 3072-3077.
- . (2009) 'Improvement of Electron Field Emission in Patterned Carbon Nanotubes by High Temperature Hydrogen Plasma Treatment'. CURRENT NANOSCIENCE, 5 (1), pp. 54-57.
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(2008) 'Ion Beam Induced Charge Studies of CdZnTe Grown by Modified Vertical Bridgman Method'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 55 (6), pp. 3741-3745.Full text is available at: http://epubs.surrey.ac.uk/369/
- . (2008) 'Ion beam induced charge (IBIC) irradiation damage study in synthetic single crystal diamond using 2.6 MeV protons'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 205 (9), pp. 2211-2215.
- . (2007) 'Modification induced by proton irradiation in Makrofol-DE polycarbonate'. PERGAMON-ELSEVIER SCIENCE LTD RADIATION MEASUREMENTS, 42 (10), pp. 1655-1660.
- . (2007) 'A review of ion beam induced charge microscopy'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 264 (2), pp. 345-360.
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(2007) 'Direct x-ray detection with conjugated polymer devices'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 91 (3) Article number ARTN 033509 doi: 10.1063/1.2748337Full text is available at: http://epubs.surrey.ac.uk/297/
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(2007) 'Mapping of polarization and detrapping effects in synthetic single crystal chemical vapor deposited diamond by ion beam induced charge imaging'. AMER INST PHYSICS JOURNAL OF APPLIED PHYSICS, 101 (6) Article number ARTN 063711 doi: 10.1063/1.2653669Full text is available at: http://epubs.surrey.ac.uk/712332/
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(2007) 'Effect of dislocations on charge carrier mobility-lifetime product in synthetic single crystal diamond'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 90 (10) Article number ARTN 102111 doi: 10.1063/1.2711754Full text is available at: http://epubs.surrey.ac.uk/712333/
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(2006) 'New materials for radiation hard semiconductor dectectors'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 557 (2), pp. 479-489.Full text is available at: http://epubs.surrey.ac.uk/7375/
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(2006) 'Temperature-dependent hole detrapping for unprimed polycrystalline chemical vapor deposited diamond'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 88 (2) Article number ARTN 023501 doi: 10.1063/1.2162673Full text is available at: http://epubs.surrey.ac.uk/244/
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(2005) 'Drift mobility and mobility-lifetime products in CdTe : Cl grown by the travelling heater method'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 52 (6), pp. 3074-3078.Full text is available at: http://epubs.surrey.ac.uk/177/
Conference papers
- . (2012) 'High resolution dual-tracer brain SPECT with a new high-performance CdTe detector'. SPRINGER EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, Milan, ITALY: 25th Annual Congress of the European-Association-of-Nuclear-Medicine (EANM) 39, pp. S230-S230.
- . (2011) 'Optical Pattern Fabrication in Amorphous Silicon Carbide with High-Energy Focused Ion Beams'. POLISH ACAD SCIENCES INST PHYSICS ACTA PHYSICA POLONICA A, Maria Curie-Sklodowska Univ, Kazimierz Dolny, POLAND: 8th International Conference on Ion Implantation and Other Applications of Ions and Electrons - ION 2010 120 (1), pp. 56-59.
- . (2010) 'Investigating the small pixel effect in CdZnTe Hard X-ray detectors the PIXIE ASIC'. IEEE Nuclear Science Symposium Conference Record (NSS/MIC), Knoxville, USA: Nuclear Science Symposium, pp. 3789-3792.
- . (2010) 'Comparison of the X-ray performance of small pixel CdTe and CZT detectors'. IEEE Nuclear Science Symposium Conference Record, Knoxville, USA: Nuclear Science Symposium, pp. 3942-3946.
- . (2009) 'High-resolution alpha spectrometry with a thin-window silicon carbide semiconductor detector'. IEEE IEEE Nuclear Science Symposium Conference Record (NSS/MIC), Orlando, USA: Nuclear Science Symposium, pp. 2201-2206.
- . (2009) 'Growth of Thick Epitaxial CdTe Films by Close Space Sublimation'. SPRINGER JOURNAL OF ELECTRONIC MATERIALS, Las Vegas, NV: 27th US Workshop on the Physics and Chemistry of II-VI Materials 38 (8), pp. 1548-1553.
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(2009) 'Non-destructive characterization and selection of X/γ-ray detector-grade CdZnTe crystals'. SPIE Proceedings of SPIE - The International Society for Optical Engineering, Beijing, China: International Symposium on Photoelectronic Detection and Imaging 2009: Terahertz and High Energy Radiation Detection Technologies and Applications 7385doi: 10.1117/12.834947
- . (2009) 'Optical contrast formation in amorphous silicon carbide with high-energy focused ion beams'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, Dresden, GERMANY: 16th International Conference on Ion Beam Modification of Materials 267 (8-9), pp. 1583-1587.
- . (2009) 'Real-time imaging of the electric field distribution in CdZnTe at low temperature'. Materials Research Society Symposium Proceedings, San Francisco, USA: MRS 2009 Spring Meeting Symposium L: Nuclear Radiation and Detection of Materials 1164, pp. 15-24.
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(2009) 'Flexible radiation dosimeters incorporating semiconducting polymer thick films'. SPIE Proceedings of SPIE - The International Society for Optical Engineering, San Diego, USA: Hard X-ray, gamma-ray, and neutron detector physics XI 7449doi: 10.1117/12.829619Full text is available at: http://epubs.surrey.ac.uk/736487/
Abstract
Flexible radiation dosimeters have been produced incorporating thick films (>1 μm) of the semiconducting polymer poly([9,9-dioctylfluorenyl-2,7-diyl]-co-bithiophene). Diode structures produced on aluminium-metallised poly(imide) substrates, and with gold top contacts, have been examined with respect to their electrical properties. The results suggest that a Schottky conduction mechanism occurs in the reverse biased diode, with a barrier to charge injection at the aluminium electrode. Optical absorption/emission spectra reveal a band gap of 2.48 eV for the polymer. The diodes have been used for direct charge detection of 17 keV X-rays, generated by a molybdenum source. Using operating voltages of -10 and -50 V respectively, sensitivities of 54 and 158 nC/mGy/cm3 have been achieved. Increasing the operating voltage shows that the diodes are stable up to approximately -200 V without significant increase in the dark current of the device (<0.2 nA).
- . (2008) 'Ion beam induced charge imaging of charge transport in CdTe and CdZnTe'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, Univ Hyderabad, Sch Phys, Hyderabad, INDIA: 18th International Conference on Ion Beam Analysis 266 (8), pp. 1300-1306.
- . (2007) 'High gain observed in X-ray induced currents in synthetic single crystal diamonds'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, Hasselt Univ, Diepenbeek-Hasselt, BELGIUM: 12th Hasselt Diamond Workshop 2007 (SBDD XII) 204 (9), pp. 3011-3016.
- . (2007) 'Charge transport in polycrystalline and single crystal synthetic diamond using ion beam induced charge imaging'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, Singapore, SINGAPORE: 10th International Conference on Nuclear Microprobe Technology and Applications held in Conjunction with the 2nd International Workshop on Proton Beam Writing 260 (1), pp. 293-298.
- . (2007) 'EBIC and IBIC imaging on polyerystalline CdTe'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Pisa, ITALY: 8th International Workshop on Radiation Imaging Detectors 576 (1), pp. 5-9.
- . (2007) 'X-ray spectroscopy and charge transport properties of CdZnTe grown by the vertical Bridgman method'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Pisa, ITALY: 8th International Workshop on Radiation Imaging Detectors 576 (1), pp. 90-94.
- . (2007) 'alpha Particle response of undoped CdMnTe'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Univ Liverpool, Liverpool, ENGLAND: 7th International Conference on Position-Senstive Detectors 573 (1-2), pp. 220-223.
- . (2007) 'IBIC characterization of charge transport in CdTe : Cl'. MAIK NAUKA/INTERPERIODICA/SPRINGER SEMICONDUCTORS, St Petersburg, RUSSIA: 8th International Workshop on Beam Injection Assessment of Microstructures in Semiconductors 41 (4), pp. 395-401.
- . (2007) 'High-energy He+ ion beam induced modification in a-SiC : H'. NATL INST OPTOELECTRONICS JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, Varna, BULGARIA: 14th International School on Condensed Matter Physics 9 (2), pp. 375-378.
- . (2006) 'Thick film compound semiconductors for X-ray imaging applications'. ELSEVIER SCIENCE BV NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Grenoble, FRANCE: 7th International Workshop on Radiation Imaging Detectors 563 (1), pp. 1-8.
Teaching
- MSc lecture courses: "Detector Instrumentation"
- MSc laboratory classes
- Level 2 lecture courses: "Exploring the Solar System"
Departmental Duties
