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:
  1. Photovoltaics the Basis for Sustainable Energy Systems and Industrial Innovations
  2. Die PV Szene heute - Technologie, Industrie, Markt
  3. The grand energy challenge 1
  4. Photovoltaics the Basis for Sustainable Energy Systems and Industrial Innovations
  5. THE IEA PVPS PROGRAMME – TOWARDS SUSTAINABLE GLOBAL DEPLOYMENT OF PV
  6. 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:
  1. 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:
  1. Kristalline Silizium Solarzellen
  2. Cost comparison of large-scale crystalline and thin film PV systems
  3. 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:
  1. PILOT-LINE CIGSSE POWER MODULE PROCESSING AND QUALIFICATION AT SHELL SOLAR
  2. CIS THIN-FILM SOLAR MODULES – AN EXAMPLE OF REMARKABLE PROGRESS IN PV
  3. 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:
  1. 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:
  1. 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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