From design to device: sustainably scaling solar cell contacts

Abstract: As we scale next-generation solar photovoltaics (CdTe, perovskites, etc.) to address the climate crisis, one key barrier is that we need better materials. Specifically, efficiency losses can occur due to poorly performing contact materials. A special kind of semiconductor contact that is transparent to sunlight and conducts holes — p-type transparent conductors (TCs) — could enable advances in a wide range of solar applications. But there’s a little complication: such a high-performing p-type TC does not yet exist. Although recent advances in theory-informed materials screenings have offered a pathway to predict such materials, so far no predicted p-type TC has high enough performance for solar. This stems from disconnects transforming predictions into results that are actually achievable in the lab, and a lag in scaling predicted materials into functional devices. In this talk, we will first visit various stages of the materials discovery process: from high-throughput computational predictions of new p-type TCs, to combinatorial synthesis of new TCs in the lab, and to fabrication of new contacts in solar devices. Next, we’ll explore another barrier: how can we design these materials with sustainability in mind so that, if they can be scaled, they do not cause further harm to people and the planet? We’ll close with insights and strategies for future materials design, and reflect on the role of materials scientists in combating climate change.

Bio: Rachel Woods-Robinson (she/her) received a BS in Physics from UCLA, and a PhD at U.C. Berkeley in the Persson group as a NSF GRFP fellow, Chancellor’s fellow, and Ross N. Tucker award recipient. Rachel’s research is driven by the critical need for renewable energy to combat climate change, and also by her obsession with crystals. In grad school she researched and designed new crystalline materials for photovoltaics by combining computational chemistry, thin film synthesis, and solar cell fabrication, which involved collaborative adventures at Berkeley Lab, NREL, SLAC, and EPFL. She recently started as a Distinguished Postdoctoral Fellow at University of Washington’s Clean Energy Institute to study environmental and human impacts of such new solar materials. In addition to research goals to curtail climate change, Rachel aims to support scientists in sharing our work accessibly and engaging collaboratively with our communities, while sneaking in outdoor adventures whenever possible. She co-founded Cycle for Science, in which scientists go on bicycle tours and visit K-12 classes to teach hands-on lessons about sustainable materials, and she instructs Cycle the Rockies (though the Wild Rockies Field Institute), an immersive month-long course in which undergrads ride bicycles across Montana to learn about local energy and climate impacts in the Rocky Mountain West.