Honors & Awards
NSF Graduate Research Fellowship, National Science Foundation (May 2017)
Ford Foundation Fellowship, National Academy of Sciences, Ford Foundation (May 2017)
EDGE Fellowship, Stanford University (May 2017)
Education & Certifications
B.S., Pennsylvania State University, Materials Science and Engineering (2016)
A.S., Cochise College, Engineering (2013)
Rafael A. Vilá. "United States Patent 62/398,751 Vertical 2D Structures for Advanced Electronic and Optoelectronic Systems", Pennsylvania State University, Oct 14, 2015
In situ crystallization kinetics of two-dimensional MoS2
2017; 5 (1)
View details for DOI 10.1088/2053-1583/aa9674
- Bottom-up synthesis of vertically oriented two-dimensional materials 2D MATERIALS 2016; 3 (4)
Two-dimensional gallium nitride realized via graphene encapsulation
2016; 15 (11): 1166-?
The spectrum of two-dimensional (2D) and layered materials 'beyond graphene' offers a remarkable platform to study new phenomena in condensed matter physics. Among these materials, layered hexagonal boron nitride (hBN), with its wide bandgap energy (∼5.0-6.0 eV), has clearly established that 2D nitrides are key to advancing 2D devices. A gap, however, remains between the theoretical prediction of 2D nitrides 'beyond hBN' and experimental realization of such structures. Here we demonstrate the synthesis of 2D gallium nitride (GaN) via a migration-enhanced encapsulated growth (MEEG) technique utilizing epitaxial graphene. We theoretically predict and experimentally validate that the atomic structure of 2D GaN grown via MEEG is notably different from reported theory. Moreover, we establish that graphene plays a critical role in stabilizing the direct-bandgap (nearly 5.0 eV), 2D buckled structure. Our results provide a foundation for discovery and stabilization of 2D nitrides that are difficult to prepare via traditional synthesis.
View details for DOI 10.1038/NMAT4742
View details for PubMedID 27571451
Growth and Tunable Surface Wettability of Vertical MoS2 Layers for Improved Hydrogen Evolution Reactions
ACS APPLIED MATERIALS & INTERFACES
2016; 8 (34): 22190-22195
Layered materials, especially the transition metal dichalcogenides (TMDs), are of interest for a broad range of applications. Among the class of TMDs, molybdenum disulfide (MoS2) is perhaps the most studied because of its natural abundance and use in optoelectronics, energy storage and energy conversion applications. Understanding the fundamental structure-property relations is key for tailoring the enhancement in the above-mentioned applications. Here, we report a controlled powder vaporization synthesis of MoS2 flower-like structures consisting of vertically grown layers of MoS2 exhibiting exposed edges. This growth is readily achievable on multiple substrates, such as graphite, silicon, and silicon dioxide. The resulting MoS2 flowers are highly crystalline and stoichiometric. Further observations using contact angle indicate that MoS2 flowers exhibit the highest reported contact angle of ∼160 ± 10°, making the material super hydrophobic. This surface wettability was further tuned by changing the edge chemistry of the MoS2 flowers using an ozone etching treatment. Hydrogen evolution reaction (HER) measurements indicate that the surface treated with UV-ozone showed a reduction in the Tafel slope from 185 to 54 mV/dec, suggesting an increase in the amount of reactive surface to generate hydrogen.
View details for DOI 10.1021/acsami.6b05848
View details for Web of Science ID 000382514100041
View details for PubMedID 27500662