## Courses

## nanoHUB-U: Thermoelectricity: From Atoms to Systems

This free self-paced course aims to introduce students to the thermoelectric theory and applications using a unique, “bottom up” approach to carrier transport that has emerged from research on molecular and nanoscale electronics.

## Scientific Overview

## Course Objectives

This self-paced course aims to introduce students to the thermoelectric theory and applications using a unique, “bottom up” approach to carrier transport that has emerged from research on molecular and nanoscale electronics. Intuition about thermoelectric relations and efficiency limits are obtained by studying a single atom. The first two units of the course introduce this new perspective and connects it to the traditional treatment of thermoelectric science. Landauer formalism provides a unified framework to study both electron and phonon transport.

The following 3 units introduce latest nanoscale and macroscale characterization techniques, the design of thermoelectric systems, and recent advances in nanoengineered thermoelectric materials and physics. Online simulations using nanoHUB will illustrate transport in realistic TE materials and energy balance in thermoelectric devices. System requirements for electronics cooling and for large scale direct heat to electricity conversion in waste heat recovery and topping cycle applications, and trade-offs beyond material’s thermoelectric figure-of-merit, in terms of the heat sink requirements, thermal stress, material usage and overall cost will be briefly introduced.

The course is taught at the level of a Purdue University course for undergraduate seniors or first year graduate students. The course also provides experts on thermoelectric science and technology with a new perspective.

## Who Should Take the Course

Thermoelectric devices are being used in a growing number of applications such as energy harvesting and precision cooling. The course should be useful for advanced undergraduates, beginning graduate students as well are researchers and practicing engineers and scientists seeking an understanding of basic concepts and how these concepts are translated into practical devices.

## Prerequisites

This course follows the nanoHUB-U philosophy of aiming to be as broadly accessible as possible to those with a background in the physical sciences or engineering. No familiarity with thermoelectric theory or technology is assumed, but an introductory level understanding of solid-state physics is necessary (e.g. energy bands, density-of-states, Fermi functions, doping etc.). A basic familiarity with topics usually covered in a two-semester college course in introductory physics is assumed. Selected topics from upper-division undergraduate courses in electricity and magnetism, thermodynamics, and quantum mechanics will be reviewed as required. A working knowledge of both integral and differential calculus is assumed. Pointers to web-based lectures that cover background topics will be provided.

## Course Outline

**Unit 1: Bottom Up Approach by Supriyo Datta**

- L1.1: Landauer Formalism for a Single Level Transport
- L1.2: Current Driven by Temperature
- L1.3: Seebeck Coefficient
- L1.4: Heat Current
- L1.5: One-Level Device
- L1.6: The Bottom-up Approach

**Unit 2: Thermoelectric Transport Parameters by Mark Lundstrom**

- L2.0: Short Introduction
- L2.1: Landauer-Boltzmann Approach
- L2.2: TE Transport Coefficients
- L2.3: Devices and Materials
- L2.4: Novel Materials and Structures
- L2.5: Lattice Thermal Conductivity
- L2.6: Boltzmann Transport Equation
- L2.7: Using Full Band Dispersions (ex. of Bi2Te3)

**Unit 3: Nanoscale and Macroscale Characterization by Ali Shakouri**

- L3.0: Introduction and Motivation
- L3.1: Micro/Nano Scale Temperature Measurement (Part 1)
- L3.2: Micro/Nano Scale Temperature Measurement (Part 2)
- L3.3: Thermoreflectance, Micro Raman, Suspended Heaters
- L3.4: Thin Film Thermoelectric Characterization
- L3.5: Thermoreflectance Laser Characterization
- L3.6: Overview of Unit 3

**Unit 4: Thermoelectric Systems by Ali Shakouri**

- L4.1: Thermoelectric Cooling and Power Generation Applications
- L4.2: Thermoelectric cost/efficiency trade off
- L4.3: Microrefrigerator on a Chip
- L4.4: Graded materials, TE leg geometry impact
- L4.5: Ballistic thermionic coolers and non-linear Peltier
- L4.6: Overview of Unit 4

**Unit 5: Recent Advances in Thermoelectric Materials and Physics by Ali Shakouri**

- L5.1: Thermionics vs. Thermoelectrics
- L5.2: Semiconductors with embedded nanoparticles
- L5.3: State-of-the-art thermoelectric materials, optimum bandgap
- L5.4: Skutterudites, Oxide thermoelectrics, Spin Seebeck, Resonant State
- L5.5: Ideal Thermoelectrics, Carnot vs. Curzon-Ahlborn limits, Some open questions
- L5.6: Overview of Unit 5, Recent reviews

## Course Resources

- A free nanoHUB.org account is required to access some course components.
- Homework exercises with solutions.
- Online quizzes to quickly assess understanding of material after most video lectures.
- An online forum, hosted by nanoHUB. Students enrolled in the course will be able to interact with one another.
- Practice exams for each module.

## Licensing

## Registration

This self-paced course is available at no cost.

**nanoHUB-U is powered by nanoHUB.org, the home for computational nanoscience and nanotechnology research, education, and collaboration.**