Materials Science and Engineering Colloquium

Speaker

Paul McIntyre, Materials Science and Engineering, Stanford University

Date Mon, 01/22/2018
Location

100 Materials Science and Engineering Building

Time 4:00 pm
Sponsor

Materials Science and Engineering

Event Type Seminar/Symposium
 

“Applications of atomic Layer deposition in solar fuel synthesis”


 


Atomic layer deposition (ALD), a cyclic form of chemical vapor deposition which occurs via a series of self-limiting chemisorption reactions, is increasingly used in fabricating microelectronic devices because of its remarkable potential for depositing a very wide range of thin films of well-controlled thickness and uniformity over a large variety of substrates.  Exciting applications of ALD in energy technologies have also emerged in recent years, particularly in photovoltaics and micro-fabricated solid oxide fuel cells.  In this presentation, I will summarize recent research in which ALD has been used to prepare stable photoelectrodes for efficient solar-driven water splitting to create hydrogen fuel.  ALD-grown TiO2 layers are found to be particularly effective in inhibiting oxidative corrosion of high-quality semiconductor absorbers and in electronically coupling these semiconductors to efficient catalysts for oxygen evolution, the kinetically-limiting step in water splitting.  This talk will describe factors influencing the electronic conductivity of ALD-TiO2, and design principles for optimizing the photovoltage of these protected semiconductor junctions.   Atomic layer deposition of TiO2-transition metal oxide alloy layers that can function as efficient oxygen evolution catalyst layers and high work function Schottky contacts for water splitting photoanodes will also be reported.  Finally, results obtained from a novel multijunction silicon photoelectrochemical cell incorporating ALD-TiO2 protection and exhibiting > 10% solar-to-hydrogen efficiency will be described.