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 Alloy Ternary or Quaternary III-V to Adjust E g & a: e.g., Al x Ga 1-x As or Ga x In 1-x N or Al 1-x-y In x Ga y P Dr. Rod Nave, HyperPhysics, Georgia State University 1 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 Alloy Ternary or Quaternary III-V to Adjust E g & a: e.g., Al x Ga 1-x As or Ga x In 1-x N or Al 1-x-y In x Ga y P E.F. Schubert, Physical Foundations of Solid State Devices (2009) 2 1
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 Alloy Ternary or Quaternary III-V to Adjust E g & a: e.g., Al x Ga 1-x As or Ga x In 1-x N or Al 1-x-y In x Ga y P E.F. Schubert, Physical Foundations of Solid State Devices (2009) 3 Angus Rocket,, The Materials Science of Semiconductors, (Springer, 2007) p. 243-244 4 2
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 5 Bandgap Engineering Light Emitting Devices The Gallium Nitride Light Emitting Diode(LED): Solid-state Semiconductor Lighting 200 m Completing the Visible Spectrum from T. Sands, UC Berkeley 6 3
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 7 Bandgap Engineering for Light Emitting Devices Bandgap Engineering: Three types Note that the band offsets are not the same! Type 1 Type 2 Type 3 Anderson & Anderson, Fundamentals of Semiconductor Devices, (McGraw Hill, 2005) Ch. 6.3 p. 317-331 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. This lecture is the text of Professor Kroemer s address on the occasion of the award. 8 4
Here we will assume the band offsets are equal. This is not usually the case. E e- Heterojunctions Type I p-type (ex., GaAs) n-type (ex., AlN) acuum Flatband 2DEG (2d e - Gas) e - 's Chemical Equilibrium 9 Here we will assume the band offsets are equal. This is not usually the case. E e- Heterojunctions Type I E C = Conduction E V = Valence n-type (ex., GaAs) p-type (ex., GaN) acuum Flatband E C Chemical Equilibrium E V 10 5
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, 2 nd Ed. (Wiley-Interscience, 1981) K.K. Ng, Complete Guide to Semiconductor Devices, 2 nd Ed. (Wiley-Interscience, 2002) Angus Rocket,, The Materials Science of Semiconductors, (Springer, 2007) 11 6