hans u. güdel department für chemie und biochemie seminar fribourg, 13.10.2009 making light
TRANSCRIPT
Hans U. Güdel Department für Chemie und Biochemie
Seminar Fribourg, 13.10.2009
Making light
2
Making light
3
Area illuminators
4
OLED Technology
5
• Light• White and coloured light• Photoluminescence, phosphors• Spectrum• Light emitting diodes (LED) • Outlook
Making light
• Light
6
• Light
Making light
7
Fiat Lux
1 in principio creavit Deus caelum et terram
2 terra autem erat inanis et vacua et tenebrae super faciem abyssi et spiritus Dei ferebatur super aquas
3 dixitque Deus fiat lux et facta est lux
4 et vidit Deus lucem quod esset bona et divisit lucem ac tenebras
First Book Moses (Genesis), Chapter 1
8
Black body radiation
Temperature: Colour:
2500°C
5000°C
7500°C
9
Black body radiation
Temperature: Colour:
5000°C
10
Human eye photoreceptors
11
Incandescent lamp
2500°C
12
Dispersion of white light
13
Making light: Additive mixing
14
Chromaticity Diagram
15
Photoluminescence
16
Kasha's Rule
17
Light emitting semiconductor
Light emission
Conduction band
Valence band
+
–
Bandgap
18
Photoluminescence of CdSe Nanoparticels
20
Fluorescent lamp
21
Luminescent phosphors
22
Lamp and display phophors
BaMgAl10O17: Eu2+
(Ce,Gd)MgB5O10: Tb3+
Y2O3: Eu3+
Judith Grimm
23
The Lanthanides
24
Coloured light
25
LED based technology
26
Light emitting diodes (LED)
Electroluminescence
Conduction band
Valence band
+
–
Bandgap
27
LED Materials
Inorganic
III – V Semiconductors
Al, Ga, In N, P, As, Sb
Al Ga As
Al Ga In P
Al Ga P
Ga N
Organic (OLED)
Polymeric luminescent molecules with conjugated electron systems
Polyphenylenvinylene
n
28
Light emitting polymer
29
Mirco Colombo citations, 3 papers
30
Diode spectra
31
White diode lamp
Y3Al2(AlO4)3: Ce3+ Diode
+
–
32
Chromaticity Diagram
33
Energy efficiency of light sources
34
Light sources
Technology steps
Electronics
Tube
analog
Tube Diode
Solid
Micro electronics
digital, solid
35
Area illuminators
36
Acknowledgment
Gabriela Frei