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Department of Physics and Astronomy Collins Research Group

Acacia Patterson Defends her Master’s Project


Graduate student Acacia Patterson has successfully defended her Master’s Thesis Project titled “Morphology-driven comprehensive charge loss analysis of organic photovoltaics processed with non-halogenated solvents.” Her project focused on quantifying all fundamental losses in the model system PCDTBT:PCBM and correlating these to morphological changes from replacing the traditional toxic halogenated solvent processing with non-halogen processing. She plans to publish this work and continue on in the lab for a PhD in Materials Science. Congratulations Acacia!

New Additive Halts Runaway Crystallinity in OPVs published in ACS Energy Letters

New work on a better processing additive for OPVs lead by gradstudent Obaid Alqahtani has been published in ACS Energy Letters. The highest OPV efficiencies, now reaching 20% solar power conversion efficiency, are obtained by solvent additives that enhance nanodomain/crystallinity formation, but often result in runnaway crystallization with small processing fluctuations. the new work shows that a new solvent additive eliminates this problem while still enhancing device performance. Gradstudent Awwad Alotaibi as well as REU undergraduate student Michael Burnes are coauthors on the study, which was published in the American Chemical Society’s lead journal for energy research. Congratulations Obaid and coauthors!

Green Additive Limits Runaway Crystallinity in PM6:Y6 Organic Solar Cells but Causes Field-Independent Geminate Recombination | ACS Energy Letters

Obaid Alqahtani Passes his PhD Defense

Obaid Alqahtani successfully defended his PhD dissertation entitled “Structure-property correlations in heterojunction organic solar cells across material systems via synchrotron X-ray techniques”. He completed his candidacy with his PhD committee including advisor Assoc. Prof. Brian Collins (Chair), Prof. Katie Zhong, and Prof. Matthew McCluskey. Obaid will continue in the group this summer as a postdoc before teaching at Prince Sattam bin Abdulaziz University in Saudi Arabia in completion of his PhD Fellowship commitment.

Congratulations Obaid!

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.

 

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