Lecture

Photodetectors and LEDs: Optoelectronics Overview

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

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 optical properties of Transition Metal Dichalcogenides (TMDCs), including band structure, excitons, and band gap tuning. It also discusses emerging photoluminescence in Monolayer MoS₂ and the integration of photodetectors in IT systems.

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)

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.

Exciton

An exciton is a bound state of an electron and an electron hole which are attracted to each other by the electrostatic Coulomb force. It is an electrically neutral quasiparticle that exists in insulators, semiconductors and some liquids. The exciton is regarded as an elementary excitation of condensed matter that can transport energy without transporting net electric charge. An exciton can form when a material absorbs a photon of higher energy than its bandgap. This excites an electron from the valence band into the conduction band.

Band diagram

In solid-state physics of semiconductors, a band diagram is a diagram plotting various key electron energy levels (Fermi level and nearby energy band edges) as a function of some spatial dimension, which is often denoted x. These diagrams help to explain the operation of many kinds of semiconductor devices and to visualize how bands change with position (band bending). The bands may be coloured to distinguish level filling. A band diagram should not be confused with a band structure plot.

Optoelectronics

Optoelectronics (or optronics) is the study and application of electronic devices and systems that find, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation.

Light-emitting diode

A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device.

Related lectures (64)

Photodetectors and LEDs

Explores optoelectronics in the IT context, focusing on TMDCs' optical properties, excitons, band gap tuning, photoluminescence, and integrated photodetectors.

Density of States in Semiconductor Devices

Explores density of states in semiconductor devices, covering electron gas, energy bands, Fermi-Dirac distribution, and band structures.

Photodetectors and LEDs

Explores the optical properties of TMDCs in optoelectronics and IT devices, focusing on band structure, excitons, and band gap tuning.

Excitons, Luminescence and LEDs

Explores excitons, luminescence, and LEDs, including their formation, impact on carrier density, and working principles.

Efficient Visible Light Emitters