Post on 09-Feb-2022
The History of Semiconductor Heterostructures Reserch:
from Early Double Heterostructure Concept to Modern Quantum Dot
Structures
Zhores Alferov
St Petersburg Academic University —Nanotechnology Research and Education Centre RAS
2
• Introduction• Transistor discovery• Discovery of laser-maser principle
and birth of optoelectronics• Heterostructure early proposals• Double heterostructure concept: classical,
quantum well and superlatticeheterostructure.“God-made” and “Man-made” crystals
• Heterostructure electronics• Quantum dot heterostructures and
development of quantum dot lasers• Future trends in heterostructure technology• Summary
3
The Nobel Prize in Physics 1956"for their researches on semiconductors
and their discovery of the transistor effect"
William Bradford Shockley1910–1989
John Bardeen1908–1991
Walter Houser Brattain1902–1987
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5
6
7W. Shockley and A. Ioffe. Prague. 1960.
88
The Nobel Prize in Physics 1964
"for fundamental work in the field of quantum electronics, which has led to the construction of oscillators
and amplifiers based on the maser-laser principle"
Charles Hard Townes
b. 1915
NicolayBasov
1922–2001
Aleksandr Prokhorov
1916–2002
99
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• N. Basov, O. Krochin and Yu. Popov(Lebedev Institute, USSR Academy of Sciences, Moscow)JETP, 40, 1879 (1961)
• M.G.A. Bernard and G. Duraffourg(Centre National d’Etudes des Telecommunications, Issy-les-Moulineaux, Seine)Physica Status Solidi, 1, 699 (1961)
Proposals of semiconductor injection lasers
1111
• January 1962: observations of superlumenscences in GaAs p-n junctions(Ioffe Institute, USSR).
• Sept.-Dec. 1962: laser action in GaAs and GaAsP p-n junctions(General Electric , IBM (USA); Lebedev Institute (USSR).
Condition of optical gain: EnF – Ep
F > Eg
Lasers and LEDs on p–n junctions
WavelengthLi
ght i
nten
sity
“+”
“–”Cleaved mirror
pn
GaAs
EnF
EpF
EgLp
DLn
Dhν
1212
The Nobel Prize in Physics 2000"for basic work on information and communication technology"
Zhores I.Alferov
b. 1930
Herbert Kroemer
b. 1928
Jack S.Kilby
1923–2005
“for his part in the invention of the integrated circuit”
“for developing semiconductor heterostructures used in high-speed- and opto-electronics”
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14
circuit
15
16
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Fundamental physical phenomena inclassical heterostructures
(a)
(b)
(c)
Fn
Ec
∆Ev
∆Ec
Fp
Electrons
Holes
Fn Ec
Ev
Fp
Electrons
Holes
Electrons
One-side InjectionPropozal — 1948 (W. Shokley)Experiment — 1965 (Zh. Alferov et al.)
SuperinjectionTheory — 1966 (Zh. Alferov et al.)Experiment — 1968 (Zh. Alferov et al.)
Diffusion in built-inquasielectric fieldTheory — 1956 (H. Kroemer)Experiment — 1967 (Zh. Alferov et al.)
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(d)
(e)Ec
Ev
FnEc
Ev
Fp
Electron and optical confinementPropozal — 1963 (Zh. Alferov, R. Kazarinov)
(H. Kroemer)Experiment — 1968 (Zh. Alferov et al.)
SuperlatticesTheory — 1962 (L.V. Keldysh)Experiment —1970 (L. Esaki et al.)Stimulated emission:Theory — 1971 (R. Kazarinov and R. Suris)Experiment —1994 (F. Capasso et al.)
Fundamental physical phenomena inclassical heterostructures
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Long journey from infinite interface recombination to ideal heterojunction
Lattice matched heterojunctions
• Ge–GaAs–1959(R. L. Anderson)
• AlGaAs–1967(Zh. Alferov et al., J. M. Woodall & H. S. Rupprecht)
• Quaternary HS (InGaAsP & AlGaAsSb)Proposal–1970 (Zh. Alferov et al.)First experiment–1972 (Antipas et al.)
Heterojunctions—a new kind of semiconductor materials:
5.40 5.56 5.72 5.88 6.04 6.20Lattice constant ( ) [300 K]Å
Ene
rgy
gap
(eV
) [30
0 K
]
2.8
2.0
1.2
0.4
AlP
GaP
GaAs
Ge
InPAlSb
GaSb
InAs
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Radiation spectrum for the first low threshold AlxGa1–xAs DHS laser at room temperature
Rad
iatio
n in
tens
ity (a
rb. u
nits
)
1.59 eV1.61 eV
(2)
1.59 eV
1.39 eV
×100
(3)
1.61 eV(1)
7100 7700 8300 8900Wavelength ( )Å
7760 7820
(2)
(1)
Wavelength ( )Å
(a)
(b)
300 K = 4300 A/cmJth
2
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Schematic representation of the DHS injection laser in the first CW-operation
at room temperature
250 µm
120
µm
200 mA
Copper
Metal
Metal
SiO2
p Al Ga As 3 µm0.25 0.75
p Al Ga As 3 µm0.25 0.75
p GaAs 0.5 µm
p GaAs 3 µm+
n GaAs
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Space station “Mir” equipped with heterostructure solar cells
Heterostructure solar cells
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Heterostructure microelectronicsHeterojunction Bipolar Transistor
NAlGaAs-n GaAs Heterojunction
Suggestion—1948 (W.Shockley)Theory—1957 (H.Kroemer)Experiment—1972 (Zh.Alferov et al.)AlGaAs HBT
HEMT—1980 (T.Mimura et al.)
Speed-power performances
J–J
100 nW 1 µW 10 µW 100 µW 1 mW 10 mW
10 ns
1 ns
100 ps
10 ps
Pro
paga
tion
dela
y
Power dissipation
∆Ec
Ev
Ec
∆Ev
F
F
∆Ec
Ev
EcE1
E0
∆Ev
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(by I. Hayashi, 1985)Heterostructure Tree
HighPower
ElectronicsLD
LED
APDPIN
DetectorArray
FET
HEMTHBT
GaAsIC
HSSolarCell's
PhasedArrayLD
Multi-Wavelength
LDPIN-FETLD-Driver
One ChipRepeater
MonolithicOEICSwitch Optical
ConnectionBetween
LSIsOpticalWiringInside
LSISSI
MSI
LSIIntegrationof Optical
and ElectronicDevices
Integrationof OpticalDevices
Integration ofBifunctional
Devices
Wide BandOptical Transition
Wavelength DivisionMultiplexity
All Optical Link
Laser DiskLaser Printer
Optical Sensor
Advanced LAN
BidirectionalVideo Network Super High Speed
Computer
One ChipComputer
IntegrationTechnology
Device Technology
ProcessTechnology
SubstrateCrystal
EpitaxiThin Film
MaterialCharacterization
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Impact of dimensionality ondensity of states
Lz
Lx
Lz
3D
0D
1D
2D
Ly
LzLx
Egap
E00 E01
E0 E1
E000 E001
Den
sity
of s
tate
sP
N
P
N
P
N
P
N
Energy
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Temperature dependence of the normalized threshold current
for different DHS lasers
(a) Bulk
(b) Quantum well
(c) Quantum wire
(d) Quantum dot
(d)
(c)
(b)
(a)(a) = 104 °CT0(b) = 285 °CT0(c) = 481 °CT0(d) = T0 ∞
–60 –40 –20 0 20 40 60Temperature (°C)
1.5
1.0
0.5
Nor
mal
ized
thre
shol
d cu
rren
t Jth— Jth =
— J Tth( )Jth(0) T
T0
= exp
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Stranski–Krastanow growth mode
• High surface energy of the substrate — thin wetting layer
• High surface energy of the film — 2D growth
• High strain energy of the film — 3D Clusters
Frank–van der Merve Volmer–Weber Stranski–Krastanow
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Cross-section of high resolution electron micrograph image of a single quantum dot for 3-ML InAs deposited; arrows indicate the boundary facets.
2 nm
001
100
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Cross-section TEM image of MBE-grown laser with InGaAs-AlGaAs QDs
Cladding layers are grown at 700 °CHigh power operation up to 1W CW
20 nm
Al Ga As matrix0.15 0.85
2 nm Al Ga As–1 nm GaAs×50 SL
0.3 0.7
2 nm Al Ga As–1 nm GaAs×47 SL
0.3 0.7
InGaAs
Vertically coupledquantum dots
Ts = 480°C
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Vertical-Cavity Surface-Emitting Lasers
Edge Emitting Laser
Vertical Cavity Surface Emitting Laser
(VCSEL)
VCSELs:• Ultralow threshold current• High beam quality• Monolitically-integrated mirrors
Planar technology, on-wafer testing, dense arrays, on-chip integration140% annual market growth. Need in reliable 1.3 & 1.55 µm VCSELs, in UV VCSELs
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Band diagram Layer sequence
Emission spectrum at room temperature
Light- and Volt-currentcharacteristics
Pulsedroom temperature
8.5 8.6 8.7Wavelength, µm
Opt
ical
pow
er (l
og.,
a.u.
) 1
0.1
0.01
0.001
8K
150K
200K
250K
Current, A
Pow
er, m
W
Volta
ge, V
12
0
4
8
80
60
40
20
00 0.5 1.0 1.5
Quantum cascade lasers
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• Evolution and revolutionary changes• Reduction of dimensionality results in improvements
Milestones of semiconductor lasers
4.3 kA/cm(1968)
2
900 A/cm(1970)
2
160 A/cm(1981)
240 A/cm
(1988)2
6 A/cm(2002)
2
19 A/cm(2000)
2
Impact of SPSL QW
105
104
103
102
10
01960 00 200565 70 75 80 85 90 95
Years
J th
2 (A
/cm
)Impact of DoubleHeterostructures
Impact of Quantum Wells
Impact of Quantum
Dots
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“Magic Leather” energy consumption
200 000
150 000
1 000 000
90 000
1 440 000
15 000 000
Energy Carrier
Total throughout the worldReserves(known andextractive)
(GWatt year)×
Consumptionrate
(GWatt)
Period ofexhaust
(years)
Oil
Gas
Coal
Nuclear Power(thermal reactors)
Total
Nuclear Power(fast reactors)
4 600
2 200
3 000
750*
11 000
11 000*
40–50
60–70
300–400
120
130
1 500
*Calculated value
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5
10
15
20
25
30
35
40
45
1950 1960 1970 1980 1990 2000 2010 2020
III-V ConcentratorMulti-junction
Concentrator AlGaAs/GaAs
Single-junction
Cryst. Si“one-sun”
Thin-Film Si
Year
50
Concentr. Si
Effi
cien
cy (%
) of s
olar
ene
rgy
conv
ersi
on
The evolution of achieved in the world till 2006 and predicted efficiencies of solar cells based on
III-V semiconductors
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Mirrors, large cells, heat pipes (early 1980s)
The tendency in concentrator PV: from large to small concentrators at high concentration ratio!
Concentrator PV installations at the Ioffe Institute
Fresnel lenses, medium cells (middle of 1980s)
Smooth lenses, small cells (late 1980s)
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Multijunction solar cells provide conversion of the solar spectrum with higher efficiency. Achievable efficiency of multijunction cells is > 50%
SiGaInP GaAs
Ge
200400600800
1000120014001600
200400600800
1000120014001600
0 0500 1000 1500 2000 2500 500 1000 1500 2000 2500
Wavelength (nm) Wavelength (nm)
Spec
tral i
rrad
ianc
e (W
/m µ
m)
2
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The theoretical limit for MJ cells
• Calculation made in the radiative limit
• Calculated for the concentration limit
• Optimum band gaps assumed 0 1 2 3 4 5 640
45
50
55
60
65
70
75 46200 x 850 W/m² AM1,5d = 333 KT
Number of pn-junctions
Effi
cien
cy (%
)
38
140
120
100
80
60
40
20
0
Inst
alle
d ca
paci
ties
(GW
)
2000 2010 20202030Year
USAEuropeJapanWorld
Evolution of the solar electrical capacities till 2030 year
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Yes!
Is Solar Energy Conversion an Option to Solve the Energy Problems
in Future?
4040
White light-emitting diodes:efficiency, controllability, reliability, life time
Today:InGaN-QW/GaN/sapphirelight-emitting chip + YAG Ce phosphor
Outlook:Monolithic microcavity LED with InGN/GN MQW active region
+ simple design– phosphor loss
+ monolithic nature+ absence of additional loss
WhitePhosphor YAG Ce
Sapphire
Buffer
n+GaN
InGaN-QW
p+GaN
Ti/Ag/AuNi/Ag/Au
White
Sapphire
Buffer
n+GaN
Ti/Ag/Au
InGaN-QW
p+GaN
Ni/Ag/AuBragg resonator GaN/AlGaN
4141
Nanostructures for high power semiconductor lasers
Laser array output power > 100 WMatrix output power > 5 kW
Laser efficiency > 75%Laser power > 10 W
5 nm
Band gap, eV
Thic
knes
s, n
m
Solid-state lasers pumping
Atmospheric and fibre optical
communication
Navigation
Energy transport in the atmosphere
and fibre
Welding and cutting
Atmospheric lidars
Medical apparatus
Fibre lasers
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1. Heterostructures — a new kind of semiconductor materials:• expensive, complicated chemically & technologically but most efficient2. Modern optoelectronics is based on heterostructure applications• DHS laser — key device of the modern optoelectronics • HS PD — the most efficient & high speed photo diode• OEIC — only solve problem of high information density of optical
communication system3. Future high speed microelectronics will mostly use
heterostructures
4. High temperature, high speed power electronics —a new broad field of heterostructure applications
5. Heterostructures in solar energy conversion:the most expensive photocells and the cheapest solar electricity producer
6. In the 21st century heterostructures in electronics will reserve only 1% for homojunctions
Summary