ECE 6542. Optoelectronics:
Devices, Systems
Lecture 1: Introduction and History
Abdallah Ougazzaden
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Ref: https://slideplayer.com/slide/9948477/
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Old TV and Telecommunication with Vacuum Tubes
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The First p-n Junction—1940: Russell Ohl
v Born: 31 January 1898 Died: 1987
v In 1940 Ohl was working with a silicon sample that had a
crack down its middle. He was using an ohmmeter to test
the electrical resistance of the sample when he noted that
when the sample was exposed to light, the current that
flowed between the two sides of the crack made a
significant jump. It was known that other semiconductors,
such as selenium, generated a small current when exposed
to light, but the cracked silicon sample was quite a
curiosity. Ohl showed the sample to his colleagues and
together they deduced that the crack was a fortunate
accident: It marked the dividing line that had occurred
when the molten silicon froze in the crucible. At that
moment, various impurities or contaminants in the silicon
had been isolated into different regions, with the crack
separating them. As a result, the silicon atoms in the
region on one side of the crack had extra electrons
around them. The other region was the opposite; its
crystallized silicon had a slight shortage of electrons.
They named the two regions p and n—p for positive-type
and n for negative-type. The barrier between the impurities
was called the p-n junction. The junction represented a
barrier, preventing the excess electrons in the n-region from
traveling over to the p-region, where atomic forces
naturally drew them.
Russell Ohl, Bell Labs
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What Changed
Between
1947 and 1997?
Famous
Quote
v“Gawd! This thing has gain!”
v Walter Brattain at Bell Telephone
Laboratories, in Building 1 on the 4th
floor of the new facility at 600
Mountain Avenue, Murray Hill, New
Jersey USA on December 16, 1947,
observing “transistor action” for the
first time. His experimental work in
collaboration with the theorist John
Bardeen resulted in the first
demonstration of solid-state
amplification in the known universe.
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The First Transistor—a Point-Contact
Bipolar Device Made of Recycled Ge!
E
h+
e- B
C
Transfer + resistor =
Transistor
First observation
of minority
carrier injection
in a
semiconductor!
N-type Ge
crystal
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Shockley Admitted That Bardeen and
Brattain Invented the Transistor!
v “John Bardeen and Walter Brattain encountered some new effects, and branching
off into a new area of theory and experiment, they invented the transistor.” –
William Shockley, in Electrons and Holes in Semiconductors – with applications
to transistor electronics, p.p. 34-35
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Bardeen & Brattain Invented the Transistor!
v William Shockley, developed the
minority carrier and junction equations.
Bardeen
Brattain
Shockley
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The Transistor “Inventors”
v John Bardeen and Walter Brattain invented the first “transfer
resistor” or transistor on December 16, 1947…
v Bill Shockley Junction Transistor
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John Bardeen—Nobel Prize in Physics for the
Transistor—1957; BCS Superconductivity—1971
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The Diamond/Zinc-Blende Semiconductors
Si, Ge, II-VI and III-V Semiconductors:
Bandgap Energy vs. “ao” Lattice Constant
Yellow, Red LEDs
Blue
Green
Red
High-Speed Electronics
Cell Phone PAs
MOSFETs, CMOS
Optical Communications
Historical Perspective
Nick Holonyak’s patent for
close-tube halide VPE
crystal growth of III-V
crystals, including
GaAs1-xPx and various
heterojunctions.
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Historical Perspective
a)
a) Typical 1960-1962 halide VPE GaAsP crystal shown with the
first GaAsP visible-spectrum laser.
b) As in a) but tilted to show one of the polished Fabry-Perot facets.
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Holonyak’s Early GaAsP Injection Laser–the
First Diode Laser Photographed with It’s Own
Light
Laser Diode Wire Bond
Contact
Red Laser
Light
0.2 mm
Scattered Light
Heat Sink
Dr. Nick Holonyak, Jr. made the first visible laser diode of GaAsP
and demonstrated it in October 1962 at General Electric in Syracuse,
NY
Historical Prespective
Allied Industrial Electronics Catalog
listing (1965) of GE’s 1965 lasers and
light-emitting diodes, with the price
reduced by 50% from 1962.
At the first semiconductor laser conference
in Schenectady, NY in November 1962, the
first GaAsP lasers were presented and
offered for sale by GE.
These GaAsP red LEDs are still being
manufactured more than 40 years later.
They are employed in the digital video disc
recording machines
About this time, it was predicted that white
LEDs would be possible.
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Wall Street Journal Advertisement—
May 1971
ª In 1971, Monsanto was the
worlds’ largest producer of
GaAs substrates and GaAsP
LEDs
ª Using hydride VPE, they
developed red and then
yellow and green N-doped
GaAsP alloys for large-scale
LED production
ª Monsanto advertisement
predicted white LED
headlights for cars!!!
Historical Perspective
v Nick Holonyak, Jr., was John
Bardeen’s first graduate student in
ECE at the University of Illinois in
1951. He graduated with a PhD in
1954 and joined Bell Labs in
Murray Hill NJ to work on the first
diffused-junction Si transistors
v He was drafted into the US Army
and joined the Signal Corps—
assigned to Yokohama, Japan
v Returned to US and joined GE
v In 1963, Holonyak moved his
research from GE in Syracuse to U
of I (Urbana IL) to join John
Bardeen.
In the photo, Holonyak and Bardeen
are looking at some of the first redorange-yellow-green (ROYG) LEDs
made in the higher-energy InGaP alloy
system. Holonyak’s group at UIUC
made the first InGaP lasers which
operated optically pumped in the red
and yellow at 77K
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Light-Emitting Diode Development
1000
Metalorganic
Chemical Vapor
Deposition
Vapor-Phase Epitaxy, Liquid-Phase Epitaxy
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100
Green
Transparent Substrate AlInGaP/GaP
Red-Orange-Yellow
Unfiltered
Incandescent Lamp
AlGaAs/AlGaAs
Red
Red Filtered
Incandescent Lamp
Edison’s First
Light Bulb
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Holonyak’s
First
Commercial
LED
GaAsP
Red
White
AlInGaP/GaAs
Red-Orange-Yellow
Yellow Filtered
Incandescent Lamp
10
169
lm/W
Shaped AlInGaP/GaP
Red-Orange-Yellow
Fluorescent Lamp
Luminous Efficacy (lm/W)
Latest
Value
White
First > 100 lm/W
Red
Blue
AlGaAs/GaAs
Red
GaAsP:N
Red-Orange-Yellow
InGaN
GaP:N Green
GaP:Zn,O
Red
~10X/decade
Ga0.6As0.4P
Red
SiC
0.1
1960
1970
1980
1990
2000
2010
Materials Properties - General
Physical Properties
• Crystal structure
• Density
• Melting point
• Viscosity
• Vapor pressure
• Porosity
Mechanical Properties
• Hardness
• Modulus of elasticity
• Poisson’s ratio
• Yield strength
• Shear strength
• Fatigue
• Fracture stength
• Creep
• Wear
• Erosion
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Materials Properties - General
Electrical Properties
• Conductivity
• Mobility of carriers
• Carrier lifetime
• Charge density
• Dielectric constant
Photonic Properties
• Transparency
• Reflectivity
• Refractive index
• Emissivity & Absorptivity
Thermal Properties
• Conductivity
• Specific heat
• Coefficient of expansion
• Emissivity
• Ablation rate
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Materials Properties - General
Chemical Properties
• Oxidation
• Hydration
• Corrosion
• Electronegativity
• Electropositivity
• Molecular weight
• Molecular number
(periodic table)
Magnetic Properties
• Permeability
• Hard versus soft
• Hysteresis
Nuclear Properties
• Half life
• Absorption cross-section
• Stability
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