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Home  /  Faculty  /  Nathan S. (Nate) Lewis

Nathan S. (Nate) Lewis

Research Summary
Semiconductor Photoelectrochemistry, Electronic Olfaction, and Scanning Tunneling Microscopy; Chemistry Animation Project
Profile

Assistant: Renee Medina

Research in the Lewis Group focuses on photoelectrochemistry and chemical vapor sensing.

Photoelectrochemistry

We study ways to harness sunlight to generate chemical fuel, specifically by splitting water to generate hydrogen. These efforts have as their final goal the creation of a photoelectrochemical cell similar to the one pictured at right.

This cell consists of nanostructured arrays of anodes and cathodes, oxidation and reduction catalysts, and a central conductive membrane that allows for ion exchange. Various subgroups are addressing the challenges inherent in developing this cell:

  • Photoanodes for Water Oxidation
  • Silicon Photocathode Arrays
  • Water-Splitting Membrane
  • Hydrogen Evolution Catalysis
  • Silicon Surface Chemistry
  • Light-Material Interactions
  • Non-conventional Solar Absorbers

Chemical Vapor Sensing

We are developing an Electronic Nose that consists of arrays of chemically sensitive conducting polymer films capable of detecting and quantifying a broad variety of analytes.

Publications

For a complete publications list, see feeds.library.caltech.edu
2025-26
Ch/ChE 140 ab. Principles and Applications of Semiconductor Photoelectrochemistry. 9 units (3-0-6); second term, 2025-26. Prerequisites: APh/EE 9 ab or instructor's permission. The properties and photoelectrochemistry of semiconductors and semiconductor/liquid junction solar cells will be discussed. Topics include optical and electronic properties of semiconductors; electronic properties of semiconductor junctions with metals, liquids, and other semiconductors, in the dark and under illumination, with emphasis on semiconductor/liquid junctions in aqueous and nonaqueous media. Problems currently facing semiconductor/liquid junctions and practical applications of these systems will be highlighted. Part a not offered 2025-26.
Instructor: Lewis (b)
2022-23
Ch 1 ab. General Chemistry. 6 units a (3-0-3) first term; b 9 units (4-0-5) second term; first, second terms, 2022-23. Lectures and recitations dealing with the principles of chemistry. First term: Chemical bonding-electronic structure of atoms, periodic properties, ionic substances, covalent bonding, Lewis representations of molecules and ions, shapes of molecules, Lewis acids and bases, Bronsted acids and bases, hybridization and resonance, bonding in solids. Second term: Chemical dynamics-spectroscopy, thermodynamics, kinetics, chemical equilibria, electrochemistry, and introduction to organic chemistry. Graded pass/fail.
Instructors: Lewis (a), Chan, Robb (b)
Ch/ChE 140 ab. Principles and Applications of Semiconductor Photoelectrochemistry. 9 units (3-0-6); second term, 2022-23. Prerequisites: APh/EE 9 ab or instructor's permission. The properties and photoelectrochemistry of semiconductors and semiconductor/liquid junction solar cells will be discussed. Topics include optical and electronic properties of semiconductors; electronic properties of semiconductor junctions with metals, liquids, and other semiconductors, in the dark and under illumination, with emphasis on semiconductor/liquid junctions in aqueous and nonaqueous media. Problems currently facing semiconductor/liquid junctions and practical applications of these systems will be highlighted. Part b not offered 2022-23.
Instructor: Lewis (a)
2019-20
Ch 1 ab. General Chemistry. Ch 1 a 6 units (3-0-3) first term; Ch 1 b 9 units (4-0-5) second term; , 2019-20. Lectures and recitations dealing with the principles of chemistry. First term: Chemical bonding-electronic structure of atoms, periodic properties, ionic substances, covalent bonding, Lewis representations of molecules and ions, shapes of molecules, Lewis acids and bases, Bronsted acids and bases, hybridization and resonance, bonding in solids. Second term: Chemical dynamics-spectroscopy, thermodynamics, kinetics, chemical equilibria, electrochemistry, and introduction to organic chemistry. Graded pass/fail.
Instructors: Lewis (a), Robb, Miller (b)
Ch/ChE 140 ab. Principles and Applications of Semiconductor Photoelectrochemistry. 9 units (3-0-6); second term, 2019-20. Prerequisites: APh/EE 9 ab or instructor's permission. The properties and photoelectrochemistry of semiconductors and semiconductor/liquid junction solar cells will be discussed. Topics include optical and electronic properties of semiconductors; electronic properties of semiconductor junctions with metals, liquids, and other semiconductors, in the dark and under illumination, with emphasis on semiconductor/liquid junctions in aqueous and nonaqueous media. Problems currently facing semiconductor/liquid junctions and practical applications of these systems will be highlighted. Part a Not offered 2019-20
Instructor: Lewis (b)