DOCSLIB.ORG

Modelling and Optimising Gaas/Al (X) Ga (1-X) As Multiple Quantum Well

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Modelling and Optimising Gaas/Al (X) Ga (1-X) As Multiple Quantum Well University of London Imperial College of Science, Technology and Medicine Department of Physics Modelling and Optimising GaAs/AlxGa1 xAs − Multiple Quantum Well Solar Cells James P. Connolly arXiv:1006.1053v1 [cond-mat.mes-hall] 5 Jun 2010 Submitted in part fulfilment of the requirements for the degree of Doctor of Philosophy in Science of the University of London and the Diploma of Imperial College, January 1997 2 Abstract The quantum well solar cell (QWSC) is a p - i - n solar cell with quantum wells in the intrinsic region. Previous work has shown that QWSCs have a greater open circuit voltage (Voc) than would be provided by a cell with the quantum well effective bandgap. This suggests that the fundamental efficiency limits of QWSCs are greater than those of single bandgap solar cells. The following work investigates QWSCs in the GaAs/AlxGa1−xAs materials system. The design and optimisation of a QWSC in this system requires studies of the voltage and current dependencies on the aluminium fraction. QWSCs with different aluminium fractions have been studied and show an increasing Voc with increasing barrier aluminium composition. The QE however decreases with increasing aluminium composition. We de- velop a model of the QE to test novel QWSC designs with a view to minimising this problem. This work concentrates on two design changes. The first deals with com- positionally graded structures in which the bandgap varies with position. This bandgap variation introduces an quasi electric field which can be used to increase minority carrier collection in the low efficiency p and n layers. This technique also increases the light flux reaching the highly efficient depletion regions. The second design change consists of coating the back of the cell with a mirror to exploit the portion of light which is not absorbed on the first pass. A model of the QE of compositionally graded QWSC solar cells with back surface mirrors is developed in order to analyse the effect of these design changes. These changes are implemented separately in a number of QWSC designs and the resulting experimental data compared with the model. An optimised design is then presented. 3 Acknowledgements The work in this thesis would not have happened without the support of a multitude of people. Keith Barnham has been a tireless source of encouragement and ideas over the years. Endless thanks to Jenny Nelson for always knowing what was wrong with models, for her encyclopaedic knowledge, and being there to recommend films, or have them recommended. Then there are all those who have passed through here, or are still here, including Jenny Barnes, Ian Ballard, Alex Zachariou, Paul Griffin, Ernest Tsui and Ned. Next come the people who actually produced the solar cells in this thesis. Christine Roberts was always ready to answer constant questions about MBE machines and AlGaAs. John Roberts’ produced the grade which worked first time, and was full of suggestions for new material tests. Malcolm Pate produced innumerable devices over the years, including the wafer squashed by the Royal Mail. Then there are collaborators overseas. Antonio Marti Vega helped me take some measurements which can’t be fitted in. Two hundred pages is quite enough! And Rosa Maria Fernandez Reyna in Madrid, who explained them to me and showed me around Madrid, including some very nice cafes and cinemas. Enrique Gr¨unbaum took TEM measurements which helped explain one of the more mystifying samples in this project, along with SIMS measurements by Federico Caccavale. The latter were enabled by Massimo Mazzer who arranged the SIMS measurements in Padua, and always had ideas for everything, including jazz concerts. And thanks to all the people who have made daily life about the department more interesting, such as Jean Leveratt for chats on level 8 at lunchtimes and solutions to all sorts of problems, Lydia, also of Level 8, and Betty Moynihan for help with the technicalities of writing up on level 3. As for finance, I thank the Greenpeace Trust who made the project possible, and who enabled me to go to the Solar World Congress. Finally, there all the people I have known, or got to know over the years. 4 There are those who are overseas - Chris and Olenka, Marc and Malar and the Smiths, Claire and the Granjon Clan. All the Tuckmans and associates in North London apart from Jo in Guatemala, Kerry and Alberta, Karen in the East, (big) Phil, (other) Phil, Hiroe, Bruce who used to be in the West, Paul and Catherine in the centre, Vince in Cambridge, the Marchants (Pete and Jo) and Kul. Then theres Tanveer (I won, I think?), Tristan, Dorothy, Dave, Wing, thanks for the coffee Steve, and Rosa in Madrid. Thanks to everyone ... ! Finally, thanks to the family: Jim, Eva, Marie Pascal, Anne Catherine, Jeanne Chantal, Isabel and Oona for the support over the years, and for coming over now and then to visit. This thesis is dedicated to my parents. Contents 1 Introduction 17 1.1 CurrentEnergyUseandAlternatives . 17 1.2 ReducingtheCostofPhotovoltaicPower . 18 1.3 IntroductiontotheOptimisationProgram . 19 2 Introduction to Solar Cells 21 2.1 Physics of Solar Cells . 21 2.1.1 Intrinsic Semiconductors in Equilibrium . 22 2.1.2 DopedSemiconductors . 24 2.2 ThePhotovoltaicEffect ....................... 26 2.2.1 Light Absorption and Pair Generation . 27 2.2.2 ChargeSeparation ...................... 29 2.2.3 Current-Voltage Characteristic of a p-n Junction in the Dark 32 2.2.4 The p-n Junction in the Light . 35 2.3 Thep-i-nSolarCell.......................... 37 2.3.1 Space Charge Region of a p-i-n Diode . 37 2.3.2 The Background Doping Problem in p-i-n Structures . 40 2.4 Limiting Efficiency of Solar Cells . 42 2.4.1 Higher Efficiency Designs . 44 2.5 Quantum Well Solar Cells . 45 2.6 TheQWSCintheAlGaAsSystem . 46 2.7 Conclusions .............................. 48 5 Contents 6 3 Quantum efficiency and short circuit current models 49 3.1 Introduction.............................. 49 3.1.1 ReviewofPreviousWork. 49 3.2 Preliminary definitions . 51 3.3 Calculation of light intensity in a QSWC . 52 3.3.1 Definitions........................... 52 3.3.2 Phaseandreflectance. 55 3.3.3 GenerationRate ....................... 55 3.4 Photocurrent ............................. 57 3.5 Intrinsicregionphotocurrent. 58 3.6 pandnRegionContributions . 59 3.6.1 Drift and Diffusion Currents . 59 3.6.2 CurrentandContinuity . 60 3.6.3 TransportEquationsfornLayers . 61 3.6.4 General Analytical Solution . 62 3.6.5 BoundaryConditions .................... 63 3.7 ConstantTransportParameters . 64 3.7.1 ZeroField........................... 64 3.7.2 Non Zero Effective Fields . 65 3.8 GradedQWSCsandNumericalSolutions . 67 3.8.1 Surface Boundary Condition in Compositionally Graded Cells.............................. 68 3.8.2 NumericalAccuracy .. .. 68 3.8.3 Comparisons of Analytical and Numerical Solutions . 70 3.9 Conclusion............................... 72 4 Model Parameters and Program Design 74 4.1 Programdesign ............................ 74 4.2 DesignandGrowthParameters . 76 4.3 OpticalParameters .......................... 78 4.3.1 IncidentFlux ......................... 78 Contents 7 4.3.2 AbsorptionCoefficient . 78 4.3.3 Reflectivity .......................... 79 4.3.4 Refractiveindex........................ 80 4.4 Transportparameters. 80 4.4.1 Band gap Parametrisations and the Quasi-Electric Field . 81 4.4.2 Minority carrier lifetime . 82 4.4.3 Mobility and Diffusion Coefficient . 83 4.4.4 Diffusion length . 83 4.4.5 Recombination velocity . 84 4.4.6 Discussion........................... 86 5 QE Modelling and Optimisation 87 5.1 UngradedCells ............................ 88 5.1.1 PreviousWork ........................ 88 5.2 Further QE Enhancements Above the Barrier Bandgap . 92 5.2.1 Light Absorption and Minority Carrier Generation . 92 5.2.2 Minority Carrier Transport . 98 5.2.3 Minority Carrier Concentration . 103 5.2.4 QEandShortCircuitCurrent . 107 5.2.5 Windows............................ 110 5.3 Further QE Enhancement Below the Barrier Bandgap . 112 5.3.1 Generation, Flux and QE in Mirrored Cells . 115 5.4 Conclusions .............................. 122 6 Device fabrication and characterisation 123 6.1 SampleGrowth ............................ 123 6.1.1 Metalorganic Vapour Phase Epitaxy (MOVPE) . 123 6.1.2 Molecular Beam Epitaxy (MBE) . 124 6.2 Processing............................... 125 6.2.1 DeviceGeometry ....................... 126 6.2.2 MirrorBackedDevices . 127 6.2.3 EffectsofProcessing . 127 Contents 8 6.3 Characterisation............................ 128 6.3.1 Photoconductivity Experiment . 128 6.3.2 Monochromatic current-voltage characteristics . 129 6.3.3 Quantum efficiency measurements . 132 6.3.4 Reflectivitymeasurement. 132 6.3.5 Externalcharacterisation. 133 6.4 Conclusion............................... 134 7 Preliminary Characterisation 136 7.1 MonochromaticIVMeasurements . 136 7.1.1 TrendsinQWSCandp-i-nDeviceMIVData. 138 7.1.2 Growth Optimisation Studies . 144 7.1.3 Passivationeffects. 146 7.1.4 Conclusions .......................... 149 7.1.5 ReflectivityMeasurements . 150 7.1.6 Conclusions .......................... 152 8 Experimental and Modelled QE Spectra 154 8.1 Principles of Data Fitting . 154 8.1.1 Samplegeometry ....................... 155 8.1.2 Samples with efficient minority carrier transport . 155 8.1.3 Samples with simplified modelling . 156 8.1.4 Samples with high surface recombination parameters . 157 8.1.5 Gradedsamples........................ 158 8.1.6 Modelling of the quantum well QE ............. 160 8.1.7 Mirrorbackedsamples . 160 8.2 GradediRegionSamples.
Load more

Recommended publications
  • Reporter272web.Pdf
    Issue 272 ▸ 15 may 2014 reporterSharing stories of Imperial’s community Imperial 2.0 Rebooting the College’s web presence to reach a growing global audience of mobile users → centre pages FESTIVAL FOR ALL SAVVY SCIENCE SAFETY SAGE Third Imperial Dr Ling Ge Ian Gillett, Festival proves on boosting Safety Director, huge hit with enterprise retires record numbers and public PAGE 10 PAGE 12 engagement PAGE 11 2 >> newsupdate www.imperial.ac.uk/reporter | reporter | 15 May 2014 • issue 272 Renewed drive for engineering through inspirational role models; and improve and increase Imperial’s recognition for equality in UK science promoting gender equality through Athena SWAN Charter awards. Imperial has joined a campaign led by the Chancellor Professor Debra Humphris, Vice Provost (Education) EDITOR’S CORNER to boost participation in technology and engineering at Imperial, said: “We want to help shatter myths and careers among women. change perceptions about women in STEM. It’s fantastic to get the Chancellor’s backing for these goals. Digital The ‘Your Life’ initiative brings together government, business, professional bodies and leading educational wonder institutions who are all working to improve We want to help shatter myths opportunities for women in science, technology, and change perceptions.” Do you remember those engineering and maths (STEM). The scheme was tentative steps when launched by Chancellor George Osborne at the Science you first dipped your Museum on 7 May. “Meeting this challenge will not be easy. It will toes into the World Wide As part of the campaign Imperial has pledged to: require a concerted effort throughout the College.
    [Show full text]
  • A Guide to Export Controls
    Foreign Affairs, Trade and Affaires étrangères, Commerce et Development Canada Développment Canada A Guide To CANADA’S EXPORT CONTROLS December 2012 Introduction The issuance of export permits is administered by the Export Controls Division (TIE) of Foreign Affairs, Trade and Development Canada (DFATD). TIE provides assistance to exporters in determining if export permits are required. It also publishes brochures and Notices to Exporters that are freely available on request and on our website www.exportcontrols.gc.ca. How to contact us: Export Controls Division (TIE) Foreign Affairs, Trade and Development Canada 111 Sussex Drive Ottawa, Ontario K1A 0G2 Telephone: (613) 996-2387 Facsimile: (613) 996-9933 Email: [email protected] For information on how to apply for an export permit and additional information on export controls please refer to our website. To enquire on the status of an export permit application: Recognized EXCOL users can check the status of an export permit application on-line. Non-recognized users can call (613) 996-2387 or email [email protected] and quote your export permit application identification (ref ID) number. Export Controls Division website: www.exportcontrols.gc.ca This Guide, at time of publication, encompasses the list of items enumerated on the Export Control List (ECL) that are controlled for export in accordance with Canadian foreign policy, including Canada’s participation in multilateral export control regimes and bilateral agreements. Unless otherwise specified, the export controls contained in this Guide apply to all destinations except the United States. Canada’s Export Control List can be found at the Department of Justice website at http://canada.justice.gc.ca/.
    [Show full text]
  • Determination of Band Structure of Gallium-Arsenide and Aluminium-Arsenide Using Density Functional Theory
    Computational Chemistry, 2016, 4, 73-82 Published Online July 2016 in SciRes. http://www.scirp.org/journal/cc http://dx.doi.org/10.4236/cc.2016.43007 Determination of Band Structure of Gallium-Arsenide and Aluminium-Arsenide Using Density Functional Theory J. A. Owolabi1, M. Y. Onimisi1, S. G. Abdu2, G. O. Olowomofe1 1Department of Physics, Nigerian Defence Academy, Kaduna, Nigeria 2Department of Physics, Kaduna State University, Kaduna, Nigeria Received 18 April 2016; accepted 2 July 2016; published 5 July 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract This research paper is on Density Functional Theory (DFT) within Local Density Approximation. The calculation was performed using Fritz Haber Institute Ab-initio Molecular Simulations (FHI- AIMS) code based on numerical atomic-centered orbital basis sets. The electronic band struc- ture, total density of state (DOS) and band gap energy were calculated for Gallium-Arsenide and Aluminium-Arsenide in diamond structures. The result of minimum total energy and computa- tional time obtained from the experimental lattice constant 5.63 A for both Gallium Arsenide and Aluminium Arsenide is −114,915.7903 eV and 64.989 s, respectively. The electronic band structure analysis shows that Aluminium-Arsenide is an indirect band gap semiconductor while Gallium-Arsenide is a direct band gap semiconductor. The energy gap results obtained for GaAs is 0.37 eV and AlAs is 1.42 eV. The band gap in GaAs observed is very small when compared to AlAs.
    [Show full text]
  • Chemical Names and CAS Numbers Final
    Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number C3H8O 1‐propanol C4H7BrO2 2‐bromobutyric acid 80‐58‐0 GeH3COOH 2‐germaacetic acid C4H10 2‐methylpropane 75‐28‐5 C3H8O 2‐propanol 67‐63‐0 C6H10O3 4‐acetylbutyric acid 448671 C4H7BrO2 4‐bromobutyric acid 2623‐87‐2 CH3CHO acetaldehyde CH3CONH2 acetamide C8H9NO2 acetaminophen 103‐90‐2 − C2H3O2 acetate ion − CH3COO acetate ion C2H4O2 acetic acid 64‐19‐7 CH3COOH acetic acid (CH3)2CO acetone CH3COCl acetyl chloride C2H2 acetylene 74‐86‐2 HCCH acetylene C9H8O4 acetylsalicylic acid 50‐78‐2 H2C(CH)CN acrylonitrile C3H7NO2 Ala C3H7NO2 alanine 56‐41‐7 NaAlSi3O3 albite AlSb aluminium antimonide 25152‐52‐7 AlAs aluminium arsenide 22831‐42‐1 AlBO2 aluminium borate 61279‐70‐7 AlBO aluminium boron oxide 12041‐48‐4 AlBr3 aluminium bromide 7727‐15‐3 AlBr3•6H2O aluminium bromide hexahydrate 2149397 AlCl4Cs aluminium caesium tetrachloride 17992‐03‐9 AlCl3 aluminium chloride (anhydrous) 7446‐70‐0 AlCl3•6H2O aluminium chloride hexahydrate 7784‐13‐6 AlClO aluminium chloride oxide 13596‐11‐7 AlB2 aluminium diboride 12041‐50‐8 AlF2 aluminium difluoride 13569‐23‐8 AlF2O aluminium difluoride oxide 38344‐66‐0 AlB12 aluminium dodecaboride 12041‐54‐2 Al2F6 aluminium fluoride 17949‐86‐9 AlF3 aluminium fluoride 7784‐18‐1 Al(CHO2)3 aluminium formate 7360‐53‐4 1 of 75 Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number Al(OH)3 aluminium hydroxide 21645‐51‐2 Al2I6 aluminium iodide 18898‐35‐6 AlI3 aluminium iodide 7784‐23‐8 AlBr aluminium monobromide 22359‐97‐3 AlCl aluminium monochloride
    [Show full text]
  • Didier Queloz Comes to Cambridge
    CavMag JANUARY 2013 Issue 9 News from the Cavendish Laboratory Inside... Editorial 2 Ground-breaking for the Battcock Centre for Experimental 3 Astrophysics DNA Origami Nanopores 4 The Higgs Boson and a Challenge 5 for Supersymmetry Spin Ices and Magnetic 6 Monopoles Wedge Issue 7 50th Anniversary of Brian 8 Josephson’s Nobel Prize Discovery Eryl Wynn-Williams and the Scale- 9 of-Two Counter First Winton Symposium - Energy 10 Efficiency Athene Donald Blogs Physics at 11 Work The Sutton Trust Summer Schools 12 in Physics Outreach and Educational Events 13 Development: Cavendish 3 - 14 Principles for Design Cavendish News 15 Didier Queloz comes to Cambridge xoplanet research is a his appointment is of great themselves at the forefront of this relatively new discipline. significance for future astronomical remarkable quest by capitalising on It started in 1995 with the research in Cambridge. As he synergies and potentials present at first definitive detection writes: Cambridge and in the country. Eof a planet orbiting a normal star beyond the Solar System ‘The search for planetary systems For the next decade, my main by Michel Mayor and Didier orbiting other stars and particularly research objective is to conduct Queloz. Since then the field has the quest to find planets similar a coherent effort towards the expanded exponentially into a to the Earth is one of the great detection and characterisation of major world-wide activity - it scientific, technological and planets with the goal of advancing is one of the areas of modern philosophical undertakings of our our understanding of their Main image: An astrophysics that has particularly time.
    [Show full text]
  • The Efficiency of Photovoltaic Systems
    UNIVERSITY OF SOUTHAMPTON The Efficiency of Photovoltaic Systems by Athanasios Gousiopoulos A thesis for the degree of Doctor of Philosophy in Electrical and Electronic Engineering Faculty of Physical Sciences and Engineering Department of Electronics and Computer Science November 2016 UNIVERSITY OF SOUTHAMPTON ABSTRACT FACULTY OF PHYSICAL SCIENCES AND ENGINEERING DEPARTMENT OF ELECTRONICS & COMPUTER SCIENCE Doctor of Philosophy The Efficiency of Photovoltaic Systems by Athanasios Gousiopoulos At this work the principle aim is to create new low cost hardware test circuitry that can emulate the behavior of solar cells under different insolation and temperature conditions. Another goal is to propose a new MPPT algorithm that could accurate and reliable estimate the maximum power operating point. The transcendental equation describing a solar cell IV characteristic contains current on both sides in a function of the form I = f (V, I). In this work, a current- independent voltage expression is derived for the maximum power point as a function of a new variable which is mathematically well defined. Validation is performed on four different photovoltaic modules. The best case scenario has shown a divergence in Pmpp of 0.08% while the worst 0.84%. The new method is examined for sensitivity, up to ± 5% on values of five fitting parameters (Rs, Rsh, n, Io, Iph), with Iph to have the higher impact effect (up to 5% error). Two topologies, of VBE multiplier, have been proposed that can reliably emulate solar cell operation. Analysis shows that both circuits have the potential to deliver good quality characteristic IV curves with small RMSE (10-3). The second improved VBE multiplier has the ability to operate over wider range of illumination and temperature conditions.
    [Show full text]
  • Device Performance of Emerging Photovoltaic Materials (Version 1)
    Device Performance of Emerging Photovoltaic Materials (Version 1) Item Type Article Authors Almora, Osbel; Baran, Derya; Bazan, Guillermo C.; Berger, Christian; Cabrera, Carlos I.; Catchpole, Kylie R.; Erten-Ela, Sule; Guo, Fei; Hauch, Jens; Ho-Baillie, Anita; Jacobsson, T. Jesper; Janssen, Rene A. J.; Kirchartz, Thomas; Kopidakis, Nikos; Li, Yongfang; Loi, Maria A.; Lunt, Richard R.; Mathew, Xavier; McGehee, Michael D.; Min, Jie; Mitzi, David B.; Nazeeruddin, Mohammad K.; Nelson, Jenny; Nogueira, Ana F.; Paetzold, Ulrich W.; Park, Nam-Gyu; Rand, Barry P.; Rau, Uwe; Snaith, Henry J.; Unger, Eva; Vaillant-Roca, Lídice; Yip, Hin-Lap; Brabec, Christoph J. Citation Almora, O., Baran, D., Bazan, G. C., Berger, C., Cabrera, C. I., Catchpole, K. R., … Brabec, C. J. (2020). Device Performance of Emerging Photovoltaic Materials (Version 1). Advanced Energy Materials, 2002774. doi:10.1002/aenm.202002774 Eprint version Publisher's Version/PDF DOI 10.1002/aenm.202002774 Publisher Wiley Journal Advanced Energy Materials Rights This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. Download date 01/10/2021 23:40:33 Item License http://creativecommons.org/licenses/by-nc/4.0/ Link to Item http://hdl.handle.net/10754/666279 PROGRESS REPORT www.advenergymat.de Device Performance of Emerging Photovoltaic Materials (Version 1) Osbel Almora,* Derya Baran, Guillermo C. Bazan, Christian Berger, Carlos I. Cabrera, Kylie R. Catchpole, Sule Erten-Ela, Fei Guo, Jens Hauch, Anita W. Y. Ho-Baillie, T.
    [Show full text]
  • Semiconductor and Magnetic Material 3
    Semiconductor and 11 Magnetic Material 2 Electronic Devices Circuits and Applications 1.1 INTRODUCTION Semiconductors are materials having electrical conductivities between those of good conductors and insulators. Semiconductors resistivity varies from 10–5 to 10+4 m. Similarly resistivity range values 10–8 to 10+6 m for conductors and from 107 to 108 m for insulators. Germanium (Ge) and Silicon (Si) are the most commonly used semiconductors and belong to Group-IV of the periodic table. They have resistivity of about 0.6 and 1.5 × 103 m respectively. Also there are certain compound semiconductors such as gallium arsenide (GaAs), indium phosphide (InP), cadmium sulphide (CdS), etc. They are formed by the combination of the elements of groups III and V. Small band gap is another important characteristic of semiconductors. Also the semiconductors have negative temperature coefficient of resistance because the number of carriers in a semiconductor will increase significantly with temperature, resulting in reduction of the resistance of the semiconductor. 1.2 SEMICONDUCTOR MATERIALS (GROUP-IV) Semiconductors are materials having electrical conductivities between those of good conductors and insulators. The elemental semiconductor such as germanium (Ge) and silicon (Si) belong to Group-IV of the periodic table and have resistivity of about 0.6 and 1.5 × 103 cm respectively. The energy band gaps of these elements of Group-IV at 0 K are given as below: C (diamond) → 5.51 eV Ge → 0.75 eV Si → 1.16 eV Sn (grey) → 0.08 eV Pd → ≈ eV We may say from above list that at room temperature (i.e., 0 K) diamond behaves as an insulator but Ge and Si are treated as semiconductors.
    [Show full text]
  • Strategic Goods (Control) Act (Chapter 300) Strategic Goods (Control) Order 2013
    1 S 10/2013 1 First published in the Government Gazette, Electronic Edition, on 11th January 2013 at 4.00 pm. No. S 00010 STRATEGIC GOODS (CONTROL) ACT (CHAPTER 300) STRATEGIC GOODS (CONTROL) ORDER 2013 ARRANGEMENT OF PARAGRAPHS Paragraph 1. Citation and commencement 2. Strategic goods and strategic goods technology 3. Revocation The Schedule In exercise of the powers conferred by section 4A(1) of the Strategic Goods (Control) Act, the Minister for Trade and Industry hereby makes the following Order: Citation and commencement 1. This Order may be cited as the Strategic Goods (Control) Order 2013 and shall come into operation on 1st February 2013. Strategic goods and strategic goods technology 2. The goods and technology specified in the Schedule shall be strategic goods and strategic goods technology, respectively, for the purposes of the Act. Revocation 3. The Strategic Goods (Control) Order 2010 (G.N. No. S 152/2010) is revoked. S 10/2013 2 2 THE SCHEDULE Paragraph 2 PART I MILITARY GOODS THE EXPORT, TRANSHIPMENT OR BRINGING IN TRANSIT OF WHICH, AND TECHNOLOGY THE EXPORT OR TRANSMISSION OF WHICH, REQUIRE A PERMIT Division 1 — Preliminary Provisions Subdivision 1 — General Notes 1. Non-controlled goods (including plant) containing one or more controlled components set out in Division 2 shall be considered as being controlled goods within Division 2 if the controlled components are the principal element of the non-controlled goods and can feasibly be removed or used for other purposes. 2. In determining whether goods are to be considered the principal element of other goods for the purposes of paragraph 1, factors such as the quantity, value and technological know-how involved and other special circumstances which might establish the goods as the principal element of those other goods must be weighed.
    [Show full text]
  • Solar Power for CO2 Mitigation Jenny Nelson, Ajay Gambhir and Ned Ekins-Daukes
    Grantham institute for climate change Briefing paper no 11 January 2014 Solar power for CO2 mitigation JEnny nElson, AJAy GAmbhir And nEd Ekins-DaukEs Executive summary Solar power repreSentS a vaSt reSource which could, in principle, meet the world’s needs for low-carbon power generation many times over. the technology to generate solar power by conversion of light to electricity (pv) and conversion of light to power via heat (solar thermal) is already proven and widely deployed. the cost reductions in solar pv over the last ten years now make it competitive with conventional, fossil fuel based grid power in some locations, and it will soon be competitive in others, including the uK. Solar power is particularly relevant to the developing world where solar resource is high and solar power with storage is likely soon to become a more cost- effective option than diesel generators. recent growth in the use of photovoltaic (pv) technology (of around 40% per year) and rapid reduction in its cost (20% per doubling of capacity) has demonstrated the potential of solar power to deliver on a large scale. the Contents international energy agency (IEA) projects that solar power could generate executive summary ..................... 1 22% of the world’s electricity by 2050. this would remove a significant fraction of the growing global carbon dioxide (CO ) emissions from fossil generation. 2 introduction ............................. 2 Such a target is ambitious but achievable: the rate of growth of installed capacity needed to meet this target is much lower than the actual average Solar energy technology and growth rate over the last 20 years.
    [Show full text]
  • Transfer State and Device Performance of Hybrid and Organic
    Spectroscopic Studies of the Charge- Transfer State and Device Performance of Hybrid and Organic Solar Cells Flurin David Eisner A thesis submitted in partial fulfilment of the degree of Doctor of Philosophy Imperial College London Department of Physics April 2019 DECLARATION OF ORIGINALITY This thesis describes the work carried out between October 2015 and December 2018 in the Experimental Solid State Physics group of Imperial College London, under the supervision of Prof. Thomas D. Anthopoulos and Prof. Jenny Nelson. The material presented herein is the product of my own work, unless stated. Where information has been derived from other sources, this has been indicated in the thesis. COPYRIGHT DECLATION The copyright of this thesis rests with the author and is made available under a Creative Commons Attribution Non-Commercial No Derivatives License (CC BY-NC-ND). Researchers are free to copy, distribute or transmit the thesis on the condition that they attribute it, that they do not use it for commercial purposes and that they do not alter, transform or build upon it. For any reuse or redistribution, researchers must make clear to others the license terms of this work. Flurin Eisner London, April 2019 2 Abstract The last few years have witnessed a remarkable explosion in advances in the field of photovoltaics (PV) based on organic semiconductors as the light absorbing material, both in terms of device efficiency and in terms of the physical understanding of the underlying processes. This thesis aims to contribute to this field by examining two different types of solar cells based on light-absorbing organic semiconductors.
    [Show full text]
  • Semiconductors Group IV Elements and III-V Compounds
    Data in Science and Technology Editor in Chief: R. Poerschke Semiconductors Group IV Elements and III-V Compounds Editor: O. Madelung Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Hong Kong Barcelona ISBN-13: 978-3-540-53150-0 e-ISBN-13: 978-3-642-45681-7 001: 10.1007/978-3-642-45681-7 Library of Congress Cataloging-in-Publication Data Semiconductors: group IV elements and II I-V compounds I editor, o. Madelung. p. cm. -- (Data in science and technology) Includes bibliographical references. ISBN 978-3-54().53150.o (Springer-Verlag Berlin Heidelberg New York : acid-free paper) I. Semiconductors--Handbooks, manuals, etc. I. Madelung, O. (Otfried) II. Series QC611.45.S46 1991 537.6'22--dc20 90-26078 CIP This work is subject to copyright All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, broadcasting, repro­ duction on microfilms or other ways, and storage in data banks_ Duplication of this publication or parts thereofis only permitted under the provisions of the German Copyright LawofSeptember9, 1965,in its current version, and a copyright fee must always be paid. Violations fall under the prosecution act ofthe German Copyright Law_ © Springer-Verlag Berlin Heidelberg 1991 The use of registered names, trademarks, etc_ in this publication does not imply, even in the absence ofa specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Typesetting: Thomson Press, Ltd_, New Delhi, India 216313040-543210 - Printed on acid-free paper Preface The frequent use of well known critical data handbooks like Beilstein, Gmelin and Landolt­ Bornstein is impeded by the fact that merely larger libraries - often far away from the scientist's working place - can afford such precious collections.
    [Show full text]