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Department of Physics and Astronomy Collins Research Group

NSLS-II’s First Liquid RSoXS Measurement

The Collins Group had the honor of conducting the first microfluidic RSoXS experiments at the new NSLS-II instrument at Brookhaven National Laboratory with beamline scientist and NIST researcher Eliot Gann (pictured top left). The new instrument sets off a new capability of spatiochemical characterization of aqueous nanostructures.

The new RSoXS instrument, funded and built by NIST at the NSLS-II, was designed to enable a microfluidic stage (pictured) to place a ~1um sheet of aqueous sample in front of the X-ray beam (itself in high vacuum). PI Brian Collins and postdoc Terry McAfee (pictured) brought their stage to enable commissioning studies of the new capability.

The insert is constructed by Protochips to be used in transmission electron microscopes. It thus enables true multimodal  (electrons and X-rays on the same sample) nanoscale investigations in-situ. Being a commercial product, it, furthermore, enables any user of the NSLS-II to bring their own insert to conduct such studies.

The first results of this study were published in the instrumentation paper describing the instrument and its capabilities.

Ferron Graduates with Physics PhD

Graduate student Thomas Ferron has graduated with his Ph.D. in Physics. His dissertation titled “Spectral model of resonant soft X-ray scattering to resolve molecule specific organization in 3D organic nanostructures” (available online) enables simultaneous statistical analysis of both chemical AND spatial information within molecular nanostructures composed primarily of carbon applied to a variety of systems. The examples include solution printed organic photovoltaic devices, block copolymer nanostructures, and aqueous polymer micelles.

Ferron will continue his work developing resonant soft X-ray scattering techniques at the National Institute of Standards and Technology as a National Research Council postdoctoral fellow.

Ferron awarded National Research Council Fellowship

Graduate student Thomas Ferron has been awarded a two-year postdoctoral fellowship from the National Research Council to conduct research at the National Institute of Standards and Technology in Gaithersburg, MD. There he will continue his research in developing and applying resonant soft X-ray scattering on polymeric or other molecular systems.

The prestigious award is a competitive fellowship from the NRC Research Associateships Program for postdoctoral fellows to work at government laboratories across the country. This includes NIST, the EPA, the Air Force Research Lab, the Army Research Lab, NOAA, etc.

Thomas will join the Polymers Processing group in the Materials Science and Engineering Division working with Dr. Daniel Sunday on polarized resonant X-ray reflectivity. Congratulations Thomas!

Collins Group Presents at REXS

Several Members of the Collins Group presented their work at the International Conference on Resonant Elastic X-ray Scattering hosted by Brookhaven National Laboratory in Riverhead, NY. Thomas Ferron, Victor Murcia, and Terry McAfee along with Brian each presented oral presentations in the plenary-only conference of ~120 attendees.

Xiaobo visit from Jiaotong University

Graduate student Xiaobo from the Ma Wei Group at Jiaotong University in Xi’an, China visited the lab. He is taking part in a collaboration to measure device physics on his high performing non-fullerene organic solar cells, and taught us a considerable amount on preparing high-performance (>15%) solar cells.

WSU Science Ambassadors promote solar science

This spring at local schools, the WSU Science Ambassadors took part in K-8 activities promoting the science of solar power. The team provided a Solar Derby activity created by Washington’s Clean Energy Institute. The events took place at Franklin Elementary School for their Science Fair and separately at Lincoln Middle School at the Palouse Family Fair, both in Pullman, WA. As seen in the pictures below, beyond kids and their families, even Butch the Cougar was able to participate in the activity.

 

Collins Group Presents at 2019 APS March Meeting

Thomas Ferron, Victor Murcia, Terry McAfee, and Brian Collins all presented at the 2019 APS March Meeting in Boston, MA. Victor, Terry, and Brian all presented in the Focus Session on “Advanced Morphological Characterization in Polymers” where Brian gave the Invited Talk for the session.

Victor presented his work on combining NEXAFS measurements and DFT of molecules to create more accurate optical models for analysis of polarized resonant soft X-ray scattering (RSoXS). Terry discussed his work with developing in-situ capabilities in RSoXS showing quantitative characterization of polymer micelle structure and dynamics without using chemical labels.

Thomas presented in the Focus Session on Organic Electronics where he discussed his recent paper on charge separation affected by molecular mixing at the donor-acceptor interface in organic photovoltaic devices.

Thomas’ organic solar cell work published in J Materials Chemistry

Graduate student Thomas Ferron’s work tying molecular mixing at interfaces to charge generation in organic solar cells (OSC) has been published in Journal of Materials Chemistry A. The work quantifies for the first time both the volume of the mixed phase and the efficiency of separating interfacial Charge Transfer states into free charges. A better than 99% correlation is revealed between these two phenomena in a model OSC system – made possible because both nanostructure and excited state dyanmics were measured on the exact same devices. Thomas’ analysis, furthermore, eliminates all other possible contributing factors to the correlation – implying a causal relationship that sharper interfaces (less mixing) causes higher charge separation efficiencies.

Critical to the study was a relatively new optical pump-electronic probe technique known as Time-Delayed Collection Field (TDCF). Although the technique is increasingly done around the world, the Collins group is the only one capable of the measurement in the US.  This is Thomas’ second 1st-Author paper published and includes as coauthors a former Undergraduate physics major Matthew Waldrip and former Masters student Michael Pope. The work was funded by the US Department of Energy as an Early Research Career Award. Congratulations to all involved!

Michael Anderson and Zachary Croft Present at SURCA

Undergraduate Seniors Michael Anderson [pictured] and Zachary Croft presented their thesis projects at the WSU Showcase for Undergraduate Research and Creative Activities (SURCA). They each put together a poster summarizing their findings and submitted their work for formal judging in the competition.

Out of more than 250 posters, Michael Anderson won one of only 3 Engineering and Physical Sciences Crimson Awards – the highest award possible, which included a $300 prize. Congratulations Michael!

Obaid Alqahtani’s Solar Cell Work Published in Advanced Energy Materials

Obaid Alqahtani’s work on structure-property relationships in small molecule organic solar cells (SM-OSCs) has been officially published online at Advanced Energy Materials. SM-OSC devices convert sunlight into power like commercial solar panels, but this new technology could significantly lower the cost of solar power because it can be printed from inks in a roll-to-roll newspaper fashion, is light-weight and flexible, and is made from earth-abundant, non-toxic materials.

Alqahtani’s work explains how the performance of SM-OSCs depends on the details of the nanostructure, which can be tuned via processing solvent and choice of molecular side-chain. In particular, it is demonstrated that high purity nano-domains results in low/delayed charge generation and severe charge trapping, but that small, mixed domains alleviates such problems to enable high performance in these devices. Future work toward commercialization should target such nanostructure for high solar power conversion efficiencies.

The work involved a large round-robin collaboration with groups across the globe including King Abdullah University of Science and Technology (KAUST, Saudi Arabia), Stanford University (USA), University of Potsdam (Germany), and University of Queensland (Australia).

Read the Paper