1. Growth Kinetics and Atomistic Mechanisms of Native Oxidation of ZrSxSe2–x and MoS2 Crystals
- Author
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Sungwook Hong, David W. Snyder, Aravind Krishnamoorthy, Stephen McDonnell, Maria Gabriela Sales, Rajiv K. Kalia, Randal Cavalero, Sean M. Oliver, Rafael Jaramillo, Akshay Singh, Subodh Tiwari, Priya Vashishta, Seong Soon Jo, Patrick M. Vora, Liqiu Yang, Joshua J. Fox, and Aiichiro Nakano
- Subjects
Condensed Matter - Materials Science ,Materials science ,Growth kinetics ,Mechanical Engineering ,Kinetics ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Bioengineering ,02 engineering and technology ,General Chemistry ,Semiconductor device ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Redox ,Chalcogen ,symbols.namesake ,Adsorption ,Chemical physics ,Phase (matter) ,symbols ,General Materials Science ,van der Waals force ,0210 nano-technology - Abstract
A thorough understanding of native oxides is essential for designing semiconductor devices. Here we report a study of the rate and mechanisms of spontaneous oxidation of bulk single crystals of ZrS$_x$Se$_{2-x}$ alloys and MoS$_2$. ZrS$_x$Se$_{2-x}$ alloys oxidize rapidly, and the oxidation rate increases with Se content. Oxidation of basal surfaces is initiated by favorable O$_2$ adsorption and proceeds by a mechanism of Zr-O bond switching, that collapses the van der Waals gaps, and is facilitated by progressive redox transitions of the chalcogen. The rate-limiting process is the formation and out-diffusion of SO$_2$. In contrast, MoS$_2$ basal surfaces are stable due to unfavorable oxygen adsorption. Our results provide insight and quantitative guidance for designing and processing semiconductor devices based on ZrS$_x$Se$_{2-x}$ and MoS$_2$, and identify the atomistic-scale mechanisms of bonding and phase transformations in layered materials with competing anions.
- Published
- 2020