functional inorganic materials · functional inorganic materials fall 2017 4 # date who topic 1...
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Functional Inorganic Materials
Prof. Dr.-Ing. habil. Mady Elbahri
Functional Inorganic Materials
CHEM-E4215 (5 cr)
Lectures (12 x): Monday 12.15 – 14.00
Thursday 14.15 – 16.00
Lecture Hall B 202b
Lecturers: Mady Elbahri (4 Lec.)
Antti Karttunen (4 Lec.)
Maarit Karppinen (4 Lec.)
MARKING
Exam 40 points: min. 15 p
Lecture Exercises 24 points:12 x 2 p; min. 15 p
Learning Diary 36 points:12 x 3 p; min. 20 p
The course provides/covers/focuses:
insights into various important/new functional inorganic
material families
applications related to e.g. new sustainable energy
technologies, optics, spintronics & other emerging fields
e.g. Low emissive coating, solar absorber,
superconductive, magnetic, ferroelectric, thermoelectric,
Li-ion and oxide-ion conductive & photoactive materials
physical phenomena behind the targeted material
functions
Lectures: 12 x ca. 2.5 h
Home problem solving 40 h
Independent homework 60 h
Exam 3 h
Learning Diary
Main purpose of the learning diary is to help you to deepen your understanding of
the subject and become more reflective of your own learning process
Do not try to re-write the lecture, or use the learning diary as a notebook
Write a short one page summary of the lecture topic and try to answer the
following questions:
- What was known and familiar to you beforehand ?
- What did you learn ?
- What remained unclear ?
Total length of the learning diary for the whole course should be appr. 20 pages
An important part of the learning diary is the last paragraph, where you should reflect
on the whole course, and especially on your own learning process!
- How well did you learn the topics ?
- Did your learning process change during the course ?
- Did your expectations of the subject matter change during the course ?
- What grade would you give yourself ?
Also remember that your learning diary provides a large part of the basis for grading
the course, so you should compile it carefully so that the teacher can assess your
learning process from it
Functional Inorganic MaterialsFall 2017
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# Date Who Topic
1 30.10. Mady Metal-based energy-saving applications
2 2.11. Mady Metal-based energy-efficient windows and solar absorbers
3 6.11. Mady Metal oxides for energy-saving applications: Past and new trends
4 9.11. Mady Materials design and new perspectives
5 13.11. Antti Thermal conductivity
6 16.11. Antti Thermoelectricity
7 20.11. Antti Ferro-, pyro-, and piezoelectricity
8 23.11. Antti Magnetic and multiferroic oxides
9 27.11. Maarit Superconducting oxides
10 30.11. Maarit Ion conductivity: Oxygen
11 4.12. Maarit Ion conductivity: Lithium
12 7.12. Maarit Hybrid materials
Mondays: 12.15 - 14.00Thursdays: 14.15 - 16.00Lecture Room: B202b
Overview of lectures 1-4
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# Date Who Topic and keywords
1 30.10. Mady Metal-based energy-saving applicationsKeywords: Concept/Terminologies, Energy-efficient Windows (Low e coating)
2 2.11. Mady Metal-based energy-saving applicationsNew prespectives & Nanocomposites
3 6.11. Mady Metal oxides for energy-saving applications: Past and new trendsOverview in Glazing, Functional Materials
4 9.11. Mady Materials design for Solar absorberTradtional design and new prespectives.
http://multimedia.3m.com 6
Energy Saving Solar Materials
Materials Design > Highly Transparent low-e Coating or Highly Absorber Films to
Enable Low-Energy Cost.
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Darmstadt University of Technology in Germany won the 2007 Solar Decathlon in Washington, D.C. with this passive house.
Passive houseControlling the Solar-Matter Interactions
http://inhabitat.com/how-to-find-the-right-window-treatments-to-save-energy-and-money/
Energy Saving House
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Total solar transmittance ( Tsol , expressed as a percent or a number between 0 and 1)
is the ratio of the total solar energy in the solar spectrum (wavelength 300–3000 nm of the
solar spectrum) that is allowed to pass through a (glazing) system, to the amount of total
solar energy falling on it.
Total solar reflectance (Rsol , expressed usually as a percent or a number between 0
and 1) is the ratio of the total solar energy that is reflected outward by the system to the
amount of total solar energy falling on it.
Total solar absorption or absorptance (Asol, expressed usually as a percent or a number
between 0 and 1) is the ratio of the total solar energy absorbed by a system to the amount
of total solar energy falling on it.
Solar-Matter Interactions
Energy Conservation
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The solar irradiation consists of two components:
Direct irradiation is the solar radiation coming
directly from the sun to the point of observation
without scattering or absorption from the
molecules and particles of the atmosphere.
Diffuse irradiation is the irradiation received after
it has been scattered by these molecules
and particles (e.g. cloudy day, winter).
Solar Irradiation
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Solar irradiance is the power per unit area received from the Sun in the form of
electromagnetic radiation in the wavelength range of the measuring instrument.
Solar radiation is peaked at visible.
https://en.wikipedia.org/wiki/Solar_irradiance
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Luminous
f(λ) being the relative sensitivity of the human eye in the photopic state,T(λ) the transmittance spectrum of a system.
Similarly, we can also define the luminous reflectance and luminous absorption .
Luminous transmittance ( Tlum) is in effect the visible transmittance weighed
by the human eye sensitivity.
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It describes the average spectral sensitivity of human visual perception of brightness.
Photopic : everyday light level luminosity functions
Scotopic : low light level luminosity functions
Luminosity Function
PhotopicScotopic
Mesopic vision is a combination of photopic vision and scotopic vision in low but not
quite dark lighting situations.
Photopic vision facilitates excellent color discrimination ability, whereas colors are indiscriminable under scotopic vision.
Use low-e coatings; heat is reflected back into the room during the
Use low-e coatings; heat is reflected back to the outside during the
Energy-efficient Windows
Double glazing units filled with inert argon.
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Energy Saving House
ObjectiveSelectivity /Visible
Controlled Emmissivity / NIR
Switchability
http://inhabitat.com/how-to-find-the-right-window-treatments-to-save-energy-and-money/
15Brian A. Korgel, Nature 500, 278–279 (2013)
Which type of solar irradiation should comes into your house?
we can have huge thermal losses through them in cold climates (winter case) and undesired heat gains in hot
climates, especially if they receive direct solar radiation (summer case).
Smart Windows
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Spectrally selective coatings are optically designed to reflect particular wavelengths, but
remain transparent to others. Such coatings are commonly used to reflect the infrared (heat)
portion of the solar spectrum while admitting more visible light.
Spectrally Selective Coatings
Note that for windows with different films on the two sides the reflectance will
depend on the side of the window surface exposed to the sun.
The term 'albedo' describes the proportion
of incident radiation reflected by a system.
A perfect reflector would have an albedo of 1,
whereas a perfect absorber would have an
albedo of 0.
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Low-e (emissive) coatings are thin films that
exhibit spectral selectivity: they are highly
transparent in the visible (VIS) part of the
electromagnetic spectrum (from 0.4 to 0.7 μm),
highly reflective in the IR (for wavelengths higher
than 0.7 μm), and absorbing in the UV (e.g.,
below 0.4 μm).
Low-e (emissive) coatings
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Visible transmittance (VT) is a fraction of the visible
spectrum of sunlight (380 to 720 nanometers), weighted
by the sensitivity of the human eye.
U-factor is the rate at which a window
conducts non-solar heat flow.
Solar heat gain (SHG) in general refers to the
heat increase of a structure (or object) in a space
that results from absorbed solar radiation.
Light-to-solar gain (LSG) It provides a gauge of
the relative efficiency of different glass or
glazing types in transmitting daylight
while blocking heat gains.
http://buildingcapacity.typepad.com/blog/2011/09/window-retrofit-dilemma-low-e-or-no-low-e-alistair-jackson-csba-leed-for-homes-ap-responds.html
Common Terminologies in the low-e Field
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Type of Solar Gain & Low e
http://www.commercialwindows.org/lowe.php
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During the winter, heat (long wave radiation) in the room naturally wants to
escape through the glass, but low-E glass reflects it back into the room keeping it
warm. If you touch a standard pane of glass in the winter it feels very cold, even
if the room itself is hot. If you touch the inner pane of Low-E glass, it feels
much much warmer.
During the summer months it is hot outside, but the low-E glass does not let
the infrared thermal radiation (long wave) pass through it reducing the overall
solar heat gain of the building. http://www.reuk.co.uk/wordpress/energy-efficiency/low-e-double-glazing/
How Does Low-e Glass Work
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There are two types of Low-E Glass – Hard Coat and Soft Coat.
How is Low-E Glass Manufactured
Hard Coat Low-E glass (Pyrolytic)
has a thin layer of molten tin poured over it while
the glass is still slightly molten. The tin welds to
the glass making the coating very strong and
difficult to scratch or remove.
Soft Coat Low-E glass ( Sputtering)
has silver, zinc, or tin applied to it in a vacuum
chamber filled with an electrically charged inert
gas. Atoms of the coating metal are sputtered
onto the surface of the glass where they stick.
Soft Coat Low-E glass has better insulating qualities than Hard Coat Low-
E glass. In double glazing units filled with inert argon, the R value (measure of resistance to heat loss) is 4.35 for soft coat, and
2.75 for hard coat. A single pane of regular glass would have an R
value of below 1.
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Sputtering is a technique used to deposit thin films of a material onto a surface ("substrate").
1) creating a gaseous plasma (forth state of matter)
and then accelerating the ions from this
plasma into some source material (a.k.a. "target")
2) the source material is eroded by the arriving
ions via energy transfer and is ejected in the form
of neutral particles - either individual atoms,
clusters of atoms or molecules.
3) As these neutral particles are ejected they will travel
in a straight line unless they come into contact with
something - other particles or a nearby surface.
4) If a "substrate" such as a Si wafer is placed in the path
of these ejected particles it will be coated by a
thin film of the source material.
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Adsorption Process
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Basic modes of thin film growth:
(a) island in the Volmer-Weber mode, 3D Volmer-Weber mode: separated islands form on the surface of substrates,
in which the interaction between atoms of film is greater than that between a
substrate and the adjacent atoms of film.
(b) layer by layer in the two-dimensional Frank-
van der Merwe mode, 2D Frank-van der Merwe mode: layer-by-layer growth, in which the
interaction between substrate and atoms of film is greater than that between
adjacent atoms of film.
(c) layer plus island in the Stranski-Krastanov
mode. layer plus island, in which one or two monolayers form first and then grow
individually.By Phuoc Huu Le and Chih Wei Luo DOI: 10.5772/65898
Thin Film Growth
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Typical transparent low-E coating materials
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There is a relationship between emissivity e and conductivity s at frequency
The higher conductivity, the lower the emissivity
There is an estimation relationship between emissivity e and sheet resistance R
There are two type of materials for transparent low emissivity coating
Semiconductive coating, i.e. ITO, FTO
the extinction coefficient k is very small such as 0.01 at 550nm, so that typical thickness is
Micrometer with acceptable absorptions
Metallic coating, i.e. Ag and Au
the extinction coefficient k is very high such as 3.5 at 550nm, so that typical thickness is below
20nm for acceptable absorptions
Type of Low e Materials
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Reflectivity as function of wavelength
Metal is a perfect reflector BUT how it can be used as a Transparent Low e
Coating?
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Transparent Gold
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Lecture assignment
What does spectrally selective coating means and
what it is impact on the Solar Heat Gain
Coefficient (SHGC)?
Describes the following terms:
a) Total solar reflectance b) 'albedo'
Best regards,
Mady