文档介绍：Plastic electronics: Outline of the course
· Introduction
· Electronic structure anic (macro)molecules
· Optical properties anic semiconductors
· Electronic transport
· Light emitting diodes
Part I:
Part II:
· Organic solid state lasers
· Xerography
· Photovoltaic cells
· Organic field effect transistors
· Organic electroluminescent displays
· Device fabrication
Plastic electronics: Outline of the course
· Introduction
· Electronic structure anic (macro)molecules
· Optical properties anic semiconductors
· Electronic transport
· Light emitting diodes
Part I:
Part II: next week
· Organic solid state lasers
· Xerography
· Photovoltaic cells
· Organic field effect transistors
· Organic electroluminescent displays
· Device fabrication
Outline
Historical remarks
Lasing anic thin films
Photonic crystals
Problems for electrical pumping
What means LASER ?
Light
Amplification by
Stimulated
Emission of
Radiation
History:
1958: Theoretical prediction (Schawlow, Townes et al., Bell-Labs)
1960: First experimental realization: Ruby laser (Al2O3 mit Cr)
(Maiman et al., Hughes Research)
1961: First continuous wave laser (HeNe)
1962: First semiconductor diode laser (GaAs)
1966: anic dye laser
2000: anic injection laser ???
Laser principle:
Optical amplification and positive feedback
Active material
|2>
Laser beam
LASING
|1> Mirror
Mirror
Pump
Some basics ... Optical amplification
|2>
Lower state population: N1
Upper state population: N2
Photon number: n
|1> Transition rate: W
Active
Medium Absorption (|1> ®|2>) ~N1Wn
Stim. Emission (|2> ®|1>) ~N2Wn
Spon. Emission (|2> ®|1>) ~N2W
Some basics ...on laser rate equations
|2>
Mirror |1> Mirror
Active
Medium
)
Inversion: D=N2-N1
units
.
arb
Photon number: dn/dt= (N2-N1)Wn-2κn+ .
ÞPower (
Threshold inversion: DTh=2κ/ W
(κ: photon loss rate; W: transition rate) Emitted 0 1 2 3 4 5 6
Pump energy (n