Robert Tang-Kong
Staff Engineer, SLAC National Accelerator Laboratory
All Publications
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Discovering exceptionally hard and wear-resistant metallic glasses by combining machine-learning with high throughput experimentation
APPLIED PHYSICS REVIEWS
2022; 9 (1)
View details for DOI 10.1063/5.0068207
View details for Web of Science ID 000741081100001
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Link between Gas Phase Reaction Chemistry and the Electronic Conductivity of Atomic Layer Deposited Titanium Oxide Thin Films.
The journal of physical chemistry letters
2021: 3625–32
Abstract
In situ monitoring of gas phase composition reveals the link between the changing gas phase chemistry during atomic layer deposition (ALD) half-cycle reactions and the electronic conductivity of ALD-TiO2 thin films. Dimethylamine ((CH3)2NH, DMA) is probed as the main product of both the TDMAT and water vapor half-reactions during the TDMAT/H2O ALD process. In-plane electronic transport characterization of the ALD grown films demonstrates that the presence of DMA, a reducing agent, in the ALD chamber throughout each half-cycle is correlated with both an increase in the films' electronic conductivity, and observation of titanium in the 3+ oxidation state by ex situ X-ray photoelectron spectroscopy analysis of the films. DMA annealing of as-grown TiO2 films in the ALD chamber produces a similar effect on their electronic characteristics, indicating the importance of DMA-induced oxygen deficiency of ALD-TiO2 in dictating the electronic conductivity of as-grown films.
View details for DOI 10.1021/acs.jpclett.1c00115
View details for PubMedID 33825465
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Interfacing Low-Temperature Atomic Layer Deposited TiO2 Electron Transport Layers with Metal Electrodes
ADVANCED MATERIALS INTERFACES
2020; 7 (8)
View details for DOI 10.1002/admi.201902054
View details for Web of Science ID 000529213900024
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Development of new Mg-Zn-Sr alloys for medical purpose
INDERSCIENCE ENTERPRISES LTD. 2020: 573–82
View details for DOI 10.1504/IJNT.2020.111327
View details for Web of Science ID 000595645700008
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Reversible Decay of Oxygen Evolution Activity of Iridium Catalysts
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
2019; 166 (14): H712–H717
View details for DOI 10.1149/2.0491914jes
View details for Web of Science ID 000489318000001
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Atomic Layer Deposited TiO2-IrOx Alloys Enable Corrosion Resistant Water Oxidation on Silicon at High Photovoltage
CHEMISTRY OF MATERIALS
2019; 31 (1): 90–100
View details for DOI 10.1021/acs.chemmater.8b03092
View details for Web of Science ID 000455558100011
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Silicon Photoanodes for Solar-Driven Oxidation of Brine: A Nanoscale, Photo-Active Analog of the Dimensionally-Stable Anode
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
2018; 165 (16): H1072–H1079
View details for DOI 10.1149/2.0791816jes
View details for Web of Science ID 000454592800001
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The Role of Catalyst Adhesion in ALD-TiO2 Protection of Water Splitting Silicon Anodes
ACS APPLIED MATERIALS & INTERFACES
2018; 10 (43): 37103-37109
View details for DOI 10.1021/acsami.8b13576
View details for Web of Science ID 000449239600057
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The Role of Catalyst Adhesion in ALD-TiO2 Protection of Water Splitting Silicon Anodes.
ACS applied materials & interfaces
2018
Abstract
Atomic layer deposited titanium dioxide (ALD-TiO2) has emerged as an effective protection layer for highly efficient semiconductor anodes which are normally unstable under the potential and pH conditions used to oxidize water in a photoelectrochemical cell. The failure modes of silicon anodes coated with an Ir/IrO x oxygen evolution catalyst layer are investigated, and poor catalyst/substrate adhesion is found to be a key factor in failed anodes. Quantitative measurements of interfacial adhesion energy show that the addition of TiO2 significantly improves reliability of anodes, yielding an adhesion energy of 6.02 ± 0.5 J/m2, more than double the adhesion energy measured in the absence of an ALD-TiO2 protection layer. These results indicate the importance of catalyst adhesion to an interposed protection layer in promoting operational stability of high efficiency semiconducting anodes during solar-driven water splitting.
View details for PubMedID 30346686