Lecture

Defects in 2D Materials

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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 most common defect types in 2D materials, including point defects like vacancies and substitutions, as well as line defects such as grain boundaries and lateral heterostructures. The influence of these defects on field-effect transistor characteristics is discussed, along with strategies to avoid grain boundaries. The lecture also delves into the quantum capacitance of 2D semiconductors and the impact of a dielectric environment on electrical transport. Various methods for defect healing, such as chemical treatments with thiols and TFSI superacid, are explored, highlighting their positive effects on reducing contact resistance and enabling single-photon sources.

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

Related concepts (32)

Field-effect transistor

The field-effect transistor (FET) is a type of transistor that uses an electric field to control the flow of current in a semiconductor. FETs (JFETs or MOSFETs) are devices with three terminals: source, gate, and drain. FETs control the flow of current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source. FETs are also known as unipolar transistors since they involve single-carrier-type operation.

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.

Transistor

A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal.

Ventricular septal defect

A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one common ventricle. The ventricular septum consists of an inferior muscular and superior membranous portion and is extensively innervated with conducting cardiomyocytes. The membranous portion, which is close to the atrioventricular node, is most commonly affected in adults and older children in the United States.

Dielectric

In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation.

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