Materials for Solar Fuels: Coupling Efficient Water Splitting Catalysts and High-Performance Photovoltaics by Atomic Layer Deposition
Abstract
Atomic layer deposition (ALD), a cyclic form of chemical vapor deposition that occurs via a series of self-limiting chemisorption reactions, is an increasingly important enabler of nanotechnology and advanced energy technologies. Exciting energy-related applications of ALD that have emerged in recent years include surface passivation of photovoltaics, electrode coating for advanced batteries, and catalyst synthesis. In this presentation, I will summarize recent research in which ALD has been used to promote stable photoelectrolysis of water for solar fuel synthesis. 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. In addition, ALD is used to alloy TiO2 with transition metal oxides that are themselves good catalysts for water oxidation and that exhibit a high work function. These layers produce high photovoltages in excess of 600 mV in n-Si Schottky MIS junction water splitting photoanodes. Such ALD-grown metal oxide alloys have the potential to become “all-in-one” catalyst/protection/hole-selective contact layers for photoelectrochemical devices. Finally, results obtained from a novel multijunction silicon photoelectrochemical cell incorporating ALD-TiO2 protection and exhibiting > 10% solar-to-hydrogen efficiency will be described.
Biography
Paul McIntyre is Rick and Melinda Reed Professor in the School of Engineering, Chair of the Department of Materials Science and Engineering and Senior Fellow of the Precourt Institute for Energy at Stanford University. He was previously Member of the Technical Staff of the central research laboratories of Texas Instruments, and was a Director’s-Funded Postdoctoral Fellow at Los Alamos National Laboratory. At Stanford, McIntyre leads a research team of graduate students, postdoctoral researchers and adjunct professors who perform basic studies of nanostructured inorganic materials for applications in electronics and energy technologies. He is best known for his work on metal oxide/semiconductor interfaces, functional metal oxide thin films, atomic layer deposition, and semiconductor nanowires. McIntyre is an author of approximately 230 archival journal papers and an inventor of 9 US patents. He has given over 120 invited presentations, plenary talks and tutorial lectures on these topics. He has received two IBM Faculty Awards, a Charles Lee Powell Foundation Faculty Scholarship and an SRC Inventor Recognition Award. McIntyre was a GCEP Distinguished Lecturer in 2010 and received the Woody White Award of the Materials Research Society in 2011. In 2016, he was the inaugural Colorado School of Mines/NREL Materials Science Distinguished Lecturer.