Lecture

Density of States in Semiconductor Devices

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In course

EE-567: Semiconductor devices II

Students will learn about understanding the fundamentals and applications of emerging nanoscale devices, materials and concepts. Remark: at least 5 students should be enrolled for the course to be given ...

Description

This lecture covers the concept of density of states in semiconductor devices, starting with the electron gas and particle in an infinite quantum well. It then progresses to crystalline solids, periodic potentials, and energy bands. The lecture also discusses the Fermi-Dirac distribution, band structures, and the distinction between metals, semiconductors, and insulators based on band gaps. The presentation concludes with examples of 1D, 2D, and 3D density of states, as well as the interpretation of excitons and photoluminescence in materials.

Instructors (2)

Mihai Adrian Ionescu

Adrian M. Ionescu is Full Professor at the Swiss Federal Institute of Technology, Lausanne, Switzerland. He received the B.S./M.S. and Ph.D. degrees from the Polytechnic Institute of Bucharest, Romania and the National Polytechnic Institute of Grenoble, France, in 1989 and 1997, respectively. He has held staff and/or visiting positions at LETI-CEA, Grenoble, France and INP Grenoble, France and Stanford University, USA, in 1998 and 1999. Dr. Ionescu has published more than 600 articles in international journals and conferences. He received many Best Paper Awards in international conferences, the Annual Award of the Technical Section of the Romanian Academy of Sciences in 1994 and the Blondel Medal in 2009 for contributions to the progress in engineering sciences in the domain of electronics. He is the 2013 recipient of the IBM Faculty Award in Engineering. He served the IEDM and VLSI conference technical committees and was the Technical Program Committee (Co)Chair of ESSDERC in 2006 and 2013. He is a member of the SATW. He is director of the Laboratory of Micro/Nanoelectronic Devices (NANOLAB).

Andras Kis

2015− Associate professor, EPFL, STI, Institute of Electrical Engineering (IEL) and Materials Science and Engineering Institute (IMX) 2008−2015 Tenure-track assistant professor at EPFL, School of Engineering (STI), Institute of Electrical Engineering (IEL) 2004−2007 Postdoctoral researcher at the University of California, Berkeley, Physics Department in the group of Prof. Zettl 2000−2003 PhD student at EPFL, Faculty of basic sciences, Institute of physics of complex matter, group of Prof. Forró 1994−1999 MS, Physics, University of Zagreb, Croatia 1994 Baccalaureate, MIOC (Mathematical and Informational Educational Center) high school

Official source

Ontological neighbourhood

Physics

Condensed matter physics: Solid-state physics

Chemistry

Organic chemistry: Organometallic chemistry

Related concepts (32)

Fermi gas

A Fermi gas is an idealized model, an ensemble of many non-interacting fermions. Fermions are particles that obey Fermi–Dirac statistics, like electrons, protons, and neutrons, and, in general, particles with half-integer spin. These statistics determine the energy distribution of fermions in a Fermi gas in thermal equilibrium, and is characterized by their number density, temperature, and the set of available energy states. The model is named after the Italian physicist Enrico Fermi.

Electronic band structure

In solid-state physics, the electronic band structure (or simply band structure) of a solid describes the range of energy levels that electrons may have within it, as well as the ranges of energy that they may not have (called band gaps or forbidden bands). Band theory derives these bands and band gaps by examining the allowed quantum mechanical wave functions for an electron in a large, periodic lattice of atoms or molecules.

Semiconductor

A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. Its conducting properties may be altered in useful ways by introducing impurities ("doping") into the crystal structure. When two differently doped regions exist in the same crystal, a semiconductor junction is created.

Semiconductor device

A semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material (primarily silicon, germanium, and gallium arsenide, as well as organic semiconductors) for its function. Its conductivity lies between conductors and insulators. Semiconductor devices have replaced vacuum tubes in most applications. They conduct electric current in the solid state, rather than as free electrons across a vacuum (typically liberated by thermionic emission) or as free electrons and ions through an ionized gas.

Fermi level

The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body. It is a thermodynamic quantity usually denoted by μ or EF for brevity. The Fermi level does not include the work required to remove the electron from wherever it came from. A precise understanding of the Fermi level—how it relates to electronic band structure in determining electronic properties; how it relates to the voltage and flow of charge in an electronic circuit—is essential to an understanding of solid-state physics.

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Semiconductor Devices II: Defects Engineering

Covers the analysis of measurements and defects engineering in semiconductor devices, including density of states and defect probing.

Effective Masses in Semiconductor Physics

Covers effective masses in semiconductors, focusing on energy bands and their implications for materials like silicon and gallium arsenide.

Dispersion Relationships: Band Structures and Density of States