Seminar: Semiconductors
Topics for Winter Term 07/08

General Topics				Team	Assistant	Date
Recommended Topics will be marked in Red
1. Introduction
	Semiconductor Products and Materials
		Give a general review
		Cover present products and their dependence on certain semiconducting properties Find some useful order criteria - either by material properties or by applications
		Cover emerging products and technologies Give a list of desirable properties that have not yet been obtained - the present research issues!
2. Basic Semiconductor Physics
	Limits and Scaling
		Generate or improve upon the basic content of chapter 3.3
		Discuss limits, e.g. leakage currents, degeneration for doping, maximum life time, tunneling in the semiconductor and through layers, avalanche break-through, ...; whereever possible with some theory.
		Describe what happens if everything is scaled down, which kinds of limits from above are critical for scaling, and new limits that may appear at small dimensions.
	Experimental Methods for Measuring Band Structures
		List and discuss major methods.
		Compare relative merits and shortcomings.
		Give some special results.
	Calculations of Band Structures
		Give a general review of the different methods.
		Compare relative merits and shortcomings.
		Give some special results.
3. Silicon: General Properties and Technologies
	Thin Film Si Solar Cells
		Amorphous Si, but essentially "thin" crystal. Si.
		Discuss developments, pro and cons, new ideas.
	Technical Diodes
		Describe the specialities of important technical diodes (tunnel diodes, varactors, fast recovery diodes, Gunn diode, IMPATT diodes, Zener diode, solar cells, ...).
		Point out where and how you have to go into material parameters and technology to achieve the desired result
4. Silicon: Special Properties and Emerging Technologies
	SOI - Methods for Wafer Production
		Discuss the basic concept and the possible advantages Overview Nov. 02
		Discuss the various methods to produce SOI wafers, give pro and cons.
		State of the art, outlook
	SOI - Product and Technologies
		Discuss possible products, pro and cons
		Compare process flow for some examples; show improvement
		Discuss special applications, e.g. MEMS
	High k Dielectrics
		Why? Overview Nov. 02
		What and How
	Micromechanics and Microsystems
		Basic concepts Optical MEMS
		Key technologies
		Key products, process integration, markets
	Wafer Bonding
		Principles, Methods, Applications
	Optical Applications of Porous Silicon
		Introduce porous Si and its optical properties
		Discuss and systemize a range of applications (Waveguide, Bragg reflector, photonic crystals, sensors, ...)
	Photonic Crystals and Semiconductors
		Introduce the concept of photonic crystals
		Basic theory, especially the differences to electrons in semiconductors
		Review attempts to produce photonic crystals with semiconductors
	Luminous Silicon
		Elucidate current developments: Prevent defect recombination, Erbium doping, Si Nanocrystals, microporous Si, "spark" - processed Si, ...
		Discuss possible mechanisms, possibilities, pro and cons.
6. Basic Laser
	New Developments in Laser Techology
		Present several special developments, e.g. VCSEL's, Quantum Cascade Lasers GRINSCH Lasers, Blue (GaN) Lasers,...
		Discuss Advantages - Disadvantages; problems, state of the art, Specialites,..
		With respect to, wavelength, power, tunablitiy, ...
7. LE Devices
	LED instead of Lightbulbs
		Present the issue, argue the pros and cons of both light sources
		Discuss the necessities for economical success
8. Speed
	"Fast" Silicon
		Present modern developments for fast Si devices, e.g.
		Si - Ge, "Strained" Si, Si - C, low e and r (and of course device size).
		Discuss state of the art, pro and cons.
	HEMT
		Present the HEMT concept
		Discuss possibilites, limitations, state of the art.
		Discuss key technologies.
10. Specialities
	Semiconducting Polymers Literature: J. Mater. Res. Vol. 19, No 7, July 2004
		First presentation: General
		Give short history, theory and chemistry. Scientifc details, ...
		Second presentation: Organic Solar Cells
		Basics, state of the art and outlook
		Third presentation: Organic ICs
		How to make them (cheaply), applications e.g. RFID
	Silicon Carbide (SiC)
		1. Discuss the basic properties of the material Crystal growth, defects, material issues.
		2. Applications, SiC devices, special technologies, state of the art, outlook
	Non-Silicon Solar Cells
		Focus on CuInSe2 and related materials
		Give properties of materials and specifics of technology
		Discuss related materials, pro and cons, e.g. HgCdTe2
		Discuss the role of crystal lattice defects and of hydrogen passivation
	Liquid Semiconductors
		Define the term
		Give examples, relate to amorphous semiconductors
		Discuss uses
	Peltier Elements and Thermoelectric Generators
		Provide simple theory
		Discuss desirable material properties; give efficiencies etc.
		Discuss existing products and technologies, give outlook.
	Liquid - semiconductor junctions
		Theory of junction
		Some practical examples (Si-HF system)

				Team	Assistant General: Dr. Riemenschneider	Date
Solar Cell Topics Basic Literature
	Markets Technologies, Companies - an Overview
		Solar Energy - what we get, we can use.
		Humans and Energy: Where it comes from, how much we use, where we are headed.
		Prices of Energy
		Solar Cells - History, where it is headed
		Literature: Photovoltaics the Basis for Sustainable Energy Systems and Industrial Innovations Die PV Szene heute - Technologie, Industrie, Markt The grand energy challenge 1 Photovoltaics the Basis for Sustainable Energy Systems and Industrial Innovations THE IEA PVPS PROGRAMME – TOWARDS SUSTAINABLE GLOBAL DEPLOYMENT OF PV Highlights of Europ. Conf. Soar Energy 2005 Barcelona
	Basic Principles of Solar Cells and Solar Cell Moduls
		Basics: IV, efficiency , fill factor, etc.. Essential material parameters (doping, life time, absorption,...). Add series resistance, add parallel resistance; discuss. Temperature dependence of efficiency etc.
		Equivalent circuits, local variations of parameter.
		Making Moduls. Problem of series resistance, shadowing
		Literature: A solar cell primer
	Crystaline Silicon Solar Cells
		Monocrystalline high-efficiency cells. Mass product vs. world record winners. n- vs. p-doping.
		Polycrystalline Cells. Making poly, making cells. Si shortage problem
		Sliver Cells and other specialities.
		Literature: Kristalline Silizium Solarzellen Cost comparison of large-scale crystalline and thin film PV systems THE CRYSTALCLEAR INTEGRATED PROJECT: next generation crystalline silicon technology from lab to production
	The CIS Family
		CuInSe2and related materials. What makes them special?
		Give properties of materials and specifics of technology; Sputtering vs. CVD?
		Specifics of technology: Series connection, stability, ...
		Discuss the role of crystal lattice defects and of hydrogen passivation2
		Discuss related materials, pro and cons, e.g. HgCdTe systems
		Literature: PILOT-LINE CIGSSE POWER MODULE PROCESSING AND QUALIFICATION AT SHELL SOLAR CIS THIN-FILM SOLAR MODULES – AN EXAMPLE OF REMARKABLE PROGRESS IN PV PROGRESS IN LOW-COST ELECTRODEPOSITION OF Cu(In,Ga)(S,Se)2 : THE CISEL PROJECT
	Amorphous and Nanocrystalline Thin-Film Si Solar Cells
		Discuss amorphous Si cells. What went wrong?
		New developments. "Thin" and "Thick" Thin-Film cells.
		Potential and specifics
		Literature: RECENT PROGRESS IN AMORPHOUS AND MICROCRYSTALLINE SILICON BASED SOLAR CELL TECHNOLOGY
	Tandem Cell, "Nano Cells and Exotica
		Discuss tandem principle
		Examples for tandem cell development
		State of the art, potential for future
		New concepts with e.g. nanodots
		Literature: ALL-SILICON TANDEM CELLS BASED ON “ARTIFICIAL” SEMICONDUCTOR SYNTHESISED USING SILICON QUANTUM DOTS IN A DIELECTRIC MATRIX
	Characterization Techniques
		Characterizing a finished solar cell. Doing it with local information. Doing it in 1 s.
		Characterizing materials (e.g. poly Si wafers or CIS layers). Which parameters are important? How to measure? How to predict the quality of cells made with the material?
		Characterizing modules. Give some specific problems.

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