Quantum Heterostructures and Devices


Prereq: Admission to a graduate program or consent of the Instructor for undergrads.


V. Mitin, V. Kochelap, M. Stroscio, “Quantum Heterostructures. Microelectronics and Optoelectronics”, Cambridge University Press, 1999. ISBN 0-521-63635-3


1. Weisbuch, B. Vinter, “Quantum Semiconductor Structures”, Academic Press, 1991.

2.S.M. Sze, “High-Speed Semiconductor Devices”, Wiley, 1990.

3.Gerald, Bastard, “Wave Mechanics Applied to Semiconductor Heterostructures", Halsted Press, 1988.

4.Ia Ipatova and V. Mitin, “Introduction to Solid State Electronics”. Addison-Wesley, 1996. ISBN 0-201-47962-1



Vladimir Mitin, Professor of EE, Room 312C, E-mail vmitin@eng.buffalo.edu



The course is designed to introduce the student to the fundamental concepts of contemporary microelectronics and nanoelectronics and tendencies in its development.



1. Introduction: Trends in microelectronics and nanoelectronics.

2. Theoretical Basis of Nanoelectronics:

a)           Introduction. Problem formulation and theoretical approach;

b)           Basic concepts of quantum physics. Waves and particles;

c)           Time and length scales. Quantum and classical regimes of transport;

d)           Schrödinger equation. Normalization, averages. Separation of variables. Variational method. Perturbation theory;

e)      Spin and statistics;

f)      Quantum transport. Landauer formula;

g)      Boltzmann equation;

h)      Self-consistent approach to kinetics. Drift-diffusion, hydrodynamics.

3. Electrons in Quantum Structures:

a)           Quantum wells. (Electron spectrum in infinitely deep square potential wells, in finite square wells, in triangular wells, density of states (DOS));

b)           Quantum wires and quantum dots (boxes). (Spectrum, DOS);

c)           Coupled quantum structures. Superlattices. (Spectrum, DOS);

d)      Excitons in quantum structures;

e)      Coulomb impurity states. Interface defects.

4. Properties of Particular Quantum Structures:

a)      Energy spectra of some semiconductor materials;

b)      Lattice mismatch. (Matched and mismatched structures, strained and

pseudomorphic structures);

c)      Single-heterojunction devices. Selective doping. (MOS structures, single


d)           Basic equations and quantitative results for a single heterostructure (simple analytical estimates, numerical analysis of selectively-doped single heterostructure, control of charge transfer);

e)           Modulation-doped quantum structures (quantum wells, n-i-p structures, delta doping).

5. Abbreviated Discussion of Lattice Vibrations in Quantum Structures:

a)           Vibrations of atomic linear chains. (Monoatomic and diatomic chains, acoustic and optical modes, density of vibrational modes);

b)           Normal coordinates. Three dimensional case. (DOS);

c)           Phonons;

d)           Lattice vibrations in quantum structures. (Acoustic and optical modes, importance of phonons in quantum structures).

6. Abbreviated Discussion of Electron Scattering in Quantum Structures:

a)      Elastic scattering in two-dimensional electron systems;

b)      Screening of a two-dimensional electron gas;

c)      Scattering by interface roughnesses, defects and impurities;

d)      Scattering of electrons by acoustic phonons in quantum wells and wires;

e)      Scattering of electrons by optical phonons in quantum wells and wires.

7. Parallel Transport in Quantum Structures:

a)      Classification of transport regimes;

b)      Linear electron transport. (Boltzmann equation., diffusion, mobility);

c)      High-field transport. (Hot electrons, streaming, velocity saturation and overshoot, Gunn effect, nonequilibrium phonons, hot-electron size effect);

d)      Hot electrons in quantum structures. (Nonlinear transport in two-dimensional electron gases, quantum wires, real-space transfer of hot electrons, nonequilibrium phonons, electron and phonon confinement, heat dissipation, mutual drag).

8. Perpendicular Transport in Quantum Structures:

a)           Double-barrier resonant tunneling. (Coherent and sequential, time-dependent Schroedinger and its numeric solution, negative differential conductivity (NDC));

b)           Superlattices. (Transconductance, NDC, Bloch oscillations, Wannier-Stark ladder);

c)           Ballistic injection devices. Single-electron transfer and Coulomb blockade.

9. Electronic Devices Based on Quantum Heterostructures:

a)         Field-effect transistors. (Principle of operation, amplification and switching);

b)         Velocity-modulation and quantum-interference transistors;

c)         Bipolar heterostructure transistors. (P-n junctions, homostructure and heterostructure bipolar transistors, Si/SiGe heterostructure bipolar transistors);

d)         Hot-electron transistors. (Ballistic-injection devices, real-space transfer devices);

e)         Applications of resonant-tunneling effect. (Oscillators, frequency multiplier, transistors, circuit applications of resonant-tunneling transistors).


Grading:   Straight scale will be used for grading with:

(90 - 100)%  -  A          (85 - 90)%   -  A-          (80 - 85)%   -  B+

(70 - 80)%   -  B           (60 - 70)%   -  B-          (50 - 60)%   -  C+

(0  - 50)%   -  C

It includes:  Two homeworks (5% each), two exams (25% each) and term paper - project (40%).

Projects: Student generated project


ABET category content as estimated by faculty member who prepared this course description: Engineering science: 3 credits or 100%


Prepared by:  Vladimir Mitin        Date:   January 6, 2004