Optics and Photovoltaics Physics 9810b Course Information: Winter 2012

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1 The University of Western Ontario Department of Physics and Astronomy Optics and Photovoltaics Physics 9810b Course Information: Winter Course Description Objective of this course is to provide the student with a solid background in optical properties of condensed matter in the solid state. Special emphasis is placed on photovoltaic materials, able to generate an electrical current from absorbed light. The course is divided in two parts. The first part of the course discusses the optical properties of materials having different electronic structures (metallic, semiconducting and insulating) and degrees of order (crystalline, micro/nanocrystalline and amorphous). Optical transitions in solids are introduced from quantum-mechanical arguments. Experimental techniques for measuring the optical properties in solids will also be presented. The second part of the course focuses on photoactive and photovoltaic materials. A number of such materials are introduced classifying them from their valence electronic structure. Different types of architectures for photovoltaic devices (including planar solar cells, thin-film solar cells and bulk hetherojunctions) are discussed in light of specific optical properties of these materials. Antirequisites: None. Prerequisites: Undergraduate-level courses in Classical Physics (Mechanics and Electromagnetism) are required. Undergraduate/graduate courses in Quantum Mechanics and Condensed Matter Physics or Material Science are a reasonable complement, but are not required. 3 lecture hours per week, 1.0 course. 2. Timetable Physics 9810b Section 001 Lecture Times: Instructor: Phone: Wednesday 8:30 am - 10:30 am, P&A Bldg room 141 Friday 9:30 am - 10:30 am, P&A Bldg room 141 First meeting: January 11, 2011, am (in front of room PAB 233). Prof. Giovanni Fanchini gfanchin@uwo.ca (519) x86238 Office: PAB 229 Web Sites: Public: WebCT: (password required) 1/10/2012 Physics 9810B: Course Information Page 1 of 5

2 3. Course Material and Office Hours Textbooks (indicative, not mandatory): First part - Optical Properties of Condensed Matter and Applications, J. Singh (Ed.) Wiley, 2006 Second part - Photovoltaic materials, Richard H. Bube, Imperial College Press, London, 1998 Others (for further reading): - Photovoltaic and photoactive materials: properties, technology, and applications J.M. Marshall and D. Dimova-Malinovska (eds.), Springer, Materials for energy conversion devices - C. C. Sorrell and J. Nowotny, Woodhead Publ., Physics of solar cells: from basic principles to advanced concepts - P. Würfel, and U. Würfel, Wiley-VCH, The physics of solar cells, Jenny Nelson, Imperial College Press, 2003 Web-site: You will find details on the course outline, course announcements, posted lecture notes and homework assignments on this web-site: Office hours: The instructor can be reached for office hours after class (Wednesday: PM and Friday PM) unless otherwise announced. I can also be reached during the week via for simple questions, or to make an appointment. I will try to reply to s as soon as possible (i.e. in a few days). Accessibility Statement Please contact the course instructor if you require material in an alternate format or if you require any other arrangements to make this course more accessible to you. You may also wish to contact Services for Students with Disabilities (SSD) at x for any specific question regarding an accommodation. 1/10/2012 Physics 9810B: Course Information Page 2 of 5

3 4. Course Content Course content is outlined in the following tables. Part 1 (Jan and Feb) Optical properties relevant to photovoltaic materials Week Sections Topic 1 Classification of solids i) Course overview. ii) Short notes of Quantum Mechanics and Quantum Mechanics in symmetrical systems: periodic boundary conditions and periodic potentials. Free electrons and electrons in solids: metals and semiconductors/insulators Optical properties of solids within the one-electron approximation I (Metals & Crystalline semiconductors) Optical properties of solids within the one-electron approximation II (Nanocrystalline, Amorphous and Anisotropic) Optical properties beyond the oneelectron approximation Heterogeneous optical solids and the photovoltaic effect Experimental determination of the properties relevant to photovoltaic materials iii) Long-range order, medium-range order, short range order. Localized electrons in crystalline, nanocrystalline and amorophous solids i) Interband optolectronic transitions as a perturbation of an ideal crystal. Constant-dipole and constant-momentum transition matrix elements and selection rules. Direct/Indirect and Allowed/Forbidden transitions ii) The optical absorption spectra of crystalline silicon and crystalline germanium. iii) Intraband optoelectronic transitions in metals. The optical absorption spectra of transparent-conducting oxides [e.g. (In 2O 3) x:(sno 2) 1-x] i) Amorphous solids: virtual crystals. The optical absorption spectra of amorphous silicon and hydrogenated amorphous silicon. ii) Nanocrystalline solids as virtual crystals. The optical absorption spectra of polycrystalline and nanocrystalline silicon iii) Selection rules and optical anisotropy: π-electrons and the optical absorption spectra of organic molecular crystals i) Localized and extended excitations in solids. Quasi-particles ii) Excitons and idealized excitonic models: Wannier-Mott and Frenkel. Excitons in crystalline silicon, amorphous silicon and organic materials. iii) Exciton recombination: radiative and non-radiative. i) Doping in crystalline and amorphous semiconductors ii) Exciton dissociation: mechanisms iii) Solar cells: microscopic and macroscopic models i) Determination of the optical properties ii) Determination of work function / Determination of defect density i) Evidence of exciton dissociation: Photoluminescence quenching. Determination of exciton diffusion length 1/10/2012 Physics 9810B: Course Information Page 3 of 5

4 Part 2 (Mar and Apr) Photovoltaic materials and devices Week Sections Topic Photovoltaic architectures: an overview Planar solar cells and thin film solar cells from Group IV Materials Solar cell assemblies from Group III-V Materials. Solar cells from Group II-VI and I/III-VI Materials. Nanoscale solar cells. i) p-n and p-i-n junctions ii) More sophisticated architectures iii) Characterization of photovoltaic devices. Solar spectrum. Determination of efficiency under specific conditions. i) Crystalline silicon solar cells ii) Polycrystalline and Amorphous silicon solar cells. Si 1-xGe x solar cells i) Degradation mechanisms in amorphous silicon solar cells i) Gallium-Arsenide preparation and GaAs solar cells. Degradation mechanisms in GaAs ii) Indium-Phosphide and InP based solar cells i) Hybrid and multijunction III-V Solar cells i) Cadmium-Telluride and related alloys ii) Copper-Indium diselenide multijunctions i) Nanoscale solar cells: quantum dot solar cells and nanowire solar cells. Problems, applications and perspectives 5 Solar cells from organic materials Bulk heterojunctions and Photochemical solar cells i) Polymeric materials for organic solar cells ii) Small molecules for organic solar cells i) Dye-sensitized solar cells 6 Ancillary photovoltaic materials i) Transparent conductors ii) Blocking layers i) Antireflection coatings 5. Evaluation Assignments and Grades Course requirements will include two take-it-home assignments, one at midterm and one at the end of the course with a few questions, but -usually- no or little numerical problems (each assignment contributes 25% of the grade and must be completed in 3 days). Questions can exhaustively be answered in maximum 2-3 written sentences. Since people usually "learn by doing," the assignments are an extremely important part of the course experience. A little discussion among your classmates and looking though books is permitted and even encouraged, but the write-up must be your own work. There will be a power presentation (20% of the grade, late March) on a specific photovoltaic-grade material and a final exam (30% of the grade) with a few multiple-choice questions, not requiring sophisticated mathematical tools. Assignments and their deadlines will be posted on the web site. Assignments must be turned in at the requested day before PM. Penalty points at -1% per day on your final marks may be applied, if you are late with final marks. The Department of Physics and Astronomy reserves the right to adjust the final course marks in rare cases, in order to conform to Departmental policy. 1/10/2012 Physics 9810B: Course Information Page 4 of 5

5 Your final grade in this course will be derived according to: Midterm Assignment 20% Final Assignment 20% Final Examination 20% Presentation 30% Participation 10% Plagiarism Scholastic offences are taken seriously and you are directed to read the appropriate policy, specifically, the definition of what constitutes a Scholastic Offence, at the following Web site: Students must write their assignments on their own. Students must acknowledge cited text by using quotation marks where appropriate and by proper referencing such as footnotes or citations. Plagiarism is a major academic offence (see Scholastic Offence Policy in the Western Academic Calendar). Assignment grades and participation grades will be posted regularly on the class WebCT site. Any errors, or appeals to your scores, must be reported to your instructor within two weeks of their initial posting. 1/10/2012 Physics 9810B: Course Information Page 5 of 5