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MSE 310-ECE 340

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Part 3: Heterojunctions - Bandgap Engineering Bandgap Energy –vs- Lattice Constant

Red 700-630 nm; 1.77-1.97eV

Orange 630-600 nm; 1.97-2.07eV

Yellow 600-570 nm; 2.07-2.18eV

Green 570-520 nm; 2.18-2.38eV

Cyan 520-480 nm; 2.38-2.58eV

Blue 480-430 nm; 2.58-2.88eV

Violet 430-400 nm; 2.88-3.10eV

Dr. Rod Nave, HyperPhysics, Georgia State University

Alloy Ternary or Quaternary III-V to Adjust Eg & a: e.g., AlxGa1-xAs or GaxIn1-xN or Al1-x-yInxGayP

MSE 310-ECE 340

Knowlton 2

Part 3: Heterojunctions - Bandgap Engineering Bandgap Energy –vs- Lattice Constant

Red 700-630 nm; 1.77-1.97eV

Orange 630-600 nm; 1.97-2.07eV

Yellow 600-570 nm; 2.07-2.18eV

Green 570-520 nm; 2.18-2.38eV

Cyan 520-480 nm; 2.38-2.58eV

Blue 480-430 nm; 2.58-2.88eV

Violet 430-400 nm; 2.88-3.10eV

E.F. Schubert, Physical Foundations of Solid State Devices (2009)

Alloy Ternary or Quaternary III-V to Adjust Eg & a: e.g., AlxGa1-xAs or GaxIn1-xN or Al1-x-yInxGayP

Knowlton 2

MSE 310-ECE 340

Knowlton 3

Part 3: Heterojunctions - Bandgap Engineering Bandgap Energy –vs- Lattice Constant

Red 700-630 nm; 1.77-1.97eV

Orange 630-600 nm; 1.97-2.07eV

Yellow 600-570 nm; 2.07-2.18eV

Green 570-520 nm; 2.18-2.38eV

Cyan 520-480 nm; 2.38-2.58eV

Blue 480-430 nm; 2.58-2.88eV

Violet 430-400 nm; 2.88-3.10eV

E.F. Schubert, Physical Foundations of Solid State Devices (2009)

Alloy Ternary or Quaternary III-V to Adjust Eg & a: e.g., AlxGa1-xAs or GaxIn1-xN or Al1-x-yInxGayP

MSE 310-ECE 340

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Part 3: Heterojunctions - Bandgap Engineering Bandgap Energy –vs- Lattice Constant

Angus R

ocket, , The M

aterials Science of Semiconductors, (S

pringer, 2007) p. 243-244

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MSE 310-ECE 340

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Heterojunctions - Bandgap Engineering III-V and II-VI Semiconductors

Use for light emitting diodes, laser diodes and detectors (photon and other high energy particles)

II-VI III-V

MSE 310-ECE 340

Knowlton 6

Bandgap Engineering Light Emitting Devices

Solid-state Semiconductor Lighting

The Gallium Nitride Light Emitting Diode(LED):

Completing the Visible Spectrum

200 m200 m200 m

from T. Sands, UC Berkeley

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MSE 310-ECE 340

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Bandgap Engineering for Light Emitting Devices

Bandgap Engineering: Quantum wells Note that the band offsets are not the same!

V. Mitin, V. Kochelap, M. Stroscio, Quantum Heterostructures: Microelectronics and Optoelectronics, (Cambridge University Press, 2005) p. 412

MSE 310-ECE 340

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Bandgap Engineering for Light Emitting Devices

Bandgap Engineering: Three types Note that the band offsets are not the same!

Herbert Kroemer, Nobel Lecture: Quasielectric fields and band offsets: teaching electrons new tricks*, REVIEWS OF MODERN PHYSICS, VOLUME 73, JULY 2001, *The 2000 Nobel Prize in Physics was shared by Zhores I. Alferov, Jack S. Kilby, and Herbert Kroemer. Thislecture is the text of Professor Kroemer’s address on the occasion of the award.

Anderson &

Anderson, F

undamentals of Sem

iconductor Devices, (M

cGraw

Hill, 2005) C

h. 6.3 p. 317-331

Type 1 Type 2 Type 3

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MSE 310-ECE 340

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Heterojunctions – Type I

Ee-Ee-Ee-

Evacuum

Flatband

ChemicalEquilibrium

Band offset

Ev

Ec

Ev

Ec

Ef

Ef

Band offset

Band offset

2DEG(2d e- Gas)

Ev

Ec

Ef

Ev

Ec

Ef

e-'s

n-type(ex., AlN)

p-type(ex., GaAs)

Here we willassume the bandoffsets are equal.This is not usuallythe case.

MSE 310-ECE 340

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Heterojunctions – Type I

Ee-Ee-Ee-

Evacuum

Flatband

ChemicalEquilibrium

Band offset

Ef

Ev

Ec

Ev

Ec

Ef

EfEV = Valence Band offset

EC = Conduction Band offset

Here we willassume the bandoffsets are equal.This is not usuallythe case.

EV

EC

p-type(ex., GaN)

n-type(ex., GaAs)

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Heterojunctions – Type 2 & 3

11

MSE 310-ECE 340

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Other References

Alfonso Franciosi and Chris G. Van de Walle, Heterojunction band offset engineering, Surface Science Reports 25 (1996) 1-140

Jasprit Singh, Electronic and Optoelectronic Properties of Semiconductor Structures(Cambridge Press, 2003) Ch. 3 .2 p. 118

V. Mitin, V. Kochelap, M. Stroscio, Quantum Heterostructures: Microelectronics and Optoelectronics, (Cambridge University Press, 2005)

Anderson & Anderson, Fundamentals of Semiconductor Devices, (McGraw Hill, 2005) Ch. 6.3 p. 317-331

K.F. Brennan, The Physics of Semiconductors – with Applications to Optoelectronic Devices, (Cambridge University Press, 1999) Ch. 11.2 p. 554

Jasprit Sing, Physics of Semiconductors and Their Heterostructures, (McGraw Hill, 1993) Ch. 6

S.M. Sze, Physics of Semiconductor Devices, 2nd Ed. (Wiley-Interscience, 1981)

K.K. Ng, Complete Guide to Semiconductor Devices, 2nd Ed. (Wiley-Interscience, 2002)

Angus Rocket, , The Materials Science of Semiconductors, (Springer, 2007)