Paulette Clancy’s proposal to Cornell’s MRSEC, the Center for Materials Research, was funded this summer to study the early-stage nucleation of moieties that form in solution and ultimately give rise to lead halide-based perovskite materials. This seed creates a new interdisciplinary effort with Prof. Lara Estroff and Peter Frazier. Estroff and her students will provide experimental data using CHESS. Frazier’s post-doc, Dr. Matthias Polocek, will contribute vital accelerated search techniques to inform the Clancy group’s molecular-scale simulations.
Proving that chalk is still an effective medium for teaching, recent Clancy group graduate James Stevenson gave an illuminating talk about his work to identify chemical species on Titan that could form liposome-like vesicles. A lively audience of astronomers, chemists and physicists, who form Cornell’s Carl Sagan Institute, discussed the role of Cassini data and excitement about next steps in the search for life on Titan.
Cornell rising senior, Aron Coraor, joined the group in the summer of 2016 under the supervision of senior graduate student, Yaset (Ace) Acevedo. Aron is bringing his strong programming skills to bear on a new project that will use coarse-grained Molecular Dynamics simulation techniques to simulate the growth of C60 (buckyballs) on graphene. While graphene is an ultra-smooth surface, its interactions with buckyballs show a strong tendency for the C60 molecules to dewet the surface.
Congratulations to James Stevenson for successfully defending his PhD thesis today. James has impressively contributed in a significant way to several fields, from the self-assembly of liposome analogs that could form in Titan’s frigid methane seas, to a metric for solvent engineering in the solution processing of lead-based hybrid organic-inorganic perovskite solar cell precursors, to the creation of a simple reactive force field suitable for complex multi-species systems, like lead-based quantum dots.
James’s work led to the creation of six papers, four of which are already published, including one in Science Advances. He will join Schrodinger Inc. in June. He will be missed as an outstanding mentor, teacher and selfless contributor to the Clancy group’s research endeavors as well as an incredibly creative force in understanding complex chemical reactions.
J.M. Stevenson, J. Lunine and P. Clancy, Membrane alternatives in worlds without oxygen: Creation of an azotosome, Nature Advances, 1 (1) e1400067 (2015).
James Raiford, BS Chem. Engr. class of ’16, has won this year’s Xerox Foundation/ Rodriguez award for excellence in undergraduate research in polymers and/or semiconductors. Jimmy’s award was based on his creativity and academic boldness in helping to create new reactive models for solar cell materials. Jimmy will be starting his PhD studies at Stanford this Fall. He received an Honorable Mention in this year’s NSF Graduate Research Fellowship program.
The award honors Prof. Ferdinand Rodriguez, a Cornell CBE professor, who was a chemical engineering pioneer in the use of polymers in semiconductor applications in the ’70s-’90s. He was also a dedicated mentor to SHPE students.
Emily Cheng has received a Cornell Engineering Learning Initiatives award for planned studies of the laser annealing of wide band gap III-V nitrides. She has been learning her trade this academic year in Professor Mike Thompson’s research lab under the mentorship of Tori Sorg, a Clancy group member. The ELI funds from Intel will allow Emily to spend the summer measuring and characterizing laser absorption in GaN and determining the temperature reached as a function of the laser power, wavelength and dwell (duration). Wide band gap materials show promise for electronic and optoelectronic applications because of their outstanding optical, electronic and thermal properties. Emily’s project with Tori will help define an appropriate dopant activation strategy that is currently a major challenge to integrating III-V nitrides in electronic devices.
Congratulations to current MS student, Nikita Sengar, who has been admitted to the PhD program. Nikita is one of only 12 students in the inaugural class of terminal MS degree students. And she is one of a select few applicants who have excelled in both graduate-level coursework and research accomplishments sufficient to be offered a place in the PhD program. Nikita already has a paper in preparation on her work to provide the mechanism by which contorted OBCB molecules selectively bind to certain chiralities of carbon nanotubes. This work has been done in conjunction with our collaborators in Lynn Loo’s group at Princeton. Nikita previously won a CECAM scholarship to attend a molecular simulation workshop in Germany.
The Cornell CBE department’s highest award for thesis excellence is named the Austin Hooey prize. This year, we are thrilled that James Stevenson has been named as a winner of this award. James is already a winner of AIChE’s CoMSEF Graduate Student award for outstanding research in 2015. He is the author of four published papers, including one in Science Advances cited by reviewers as “highly important” and that became one of that new journal’s top 10 papers of the year in 2015. At least two more important papers are in preparation. The breadth of his research deserves a mention: He has contributed to our understanding of Titan’s biochemistry, the formation of chalcogenide quantum dots in solution, and for metal halide perovskites, and algorithmic development and new inter- and intra- molecular force fields. The Hooey award also recognizes service to the group and the community and James has done this “in spades.” In the group, he led and carefully mentored his own team of four graduate students and six undergraduates to many awards and great success. He spent a year volunteering at the Sciencenter, helping K-12 students to create a presentation about energy to the young Sciencenter visitors and their parents. This has certainly been a banner year for the Clancy group this year, winning the Austin Hooey prize in 2015 (Saathoff) and again in 2016 (Stevenson).
This exciting new paper in ACS Nano is a collaboration between the research groups of Profs. Will Dichtel, who synthesized the graphene nanoribbons from the “bottom up,” and Lynn Loo, who made the devices and the Clancy group. Our contribution involved showing the strongly deleterious effect of misaligned nanoribbons on the band gap of the system and the fact that the side-chains play little or no role in the electronic properties, except by keeping the GNRs apart.
Gao, F. Uribe-Romo, J.D. Saathoff, H. Arslan, C. R. Crick, S. J. Hein, B. Itin, P. Clancy, W.R. Dichtel and Y.-L. Loo, Accumulation mode electron transport in transistors of solution-synthesized and structurally precise graphene nanoribbons, ACS Nano, DOI: 10.1021/acsnano.6b00643 (2016).
Ace’s paper in Langmuir used a variety of complementary multiscale methods: molecular-scale coarse-grained Molecular Dynamics, mesoscale Kinetic Monte Carlo, and a novel continuum method to uncover the strengths and limitations of these methods to study heteroepitactical growth (i.e, growth of A on B where A and B have different preferred crystal structures). The 3D growth and the unexpected tendency for lower temperature growth to produce smoother films was also seen in experiments by Breuer and Witte.
Y. M. Acevedo, R.A. Cantrell, P. G. Berard, D. L. Koch and P. Clancy, Multiscale Simulation and Theoretical Description of Multilayer Heteroepitactic Growth of C60 on Pentacene, Langmuir, 32(12), 3045-3056 (2016)