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Summary Sentence: Join Materials Science and Engineering as they present Dr. Shiijung Sun from the Massachusetts Institute of Technology, Photovoltaics Research Laboratory.
Full Summary: No summary paragraph submitted.
Shiijung Sun
Shiijung Sun, Research Scientist
Massachusetts Institute of Technology, Photovoltaics Research Laboratory
Abstract:
Traditionally materials science is divided into the organic and inorganic fields. Interdisciplinary research on hybrid organic-inorganic materials has opened new avenues for functional materials design. For example, the discovery of semiconducting hybrid perovskites that can achieve > 25% solar-to-electricity efficiency has attracted tremendous interest from both academia and the energy industry. The enormous structural and chemical diversity of hybrid materials leads to technical applications beyond their purely organic or inorganic counterparts. However, engineering this complex composition space also posed new challenges to materials chemists.
In this seminar I will present the latest advances in materials discovery resolving two critical challenges hindering the widespread commercial adoption of state-of-the-art semiconducting hybrid materials: 1) their rapid degradation under environmental stimuli and 2) the chemical toxicity. Exemplified by two experimental campaign, I will explain how data-driven “accelerated search” and “smart search” tools effectively guide materials design, and how synchrotron-based advanced characterization can reveal the fundamental crystal chemistry of the newly discovered materials.
In the first part of my talk, I will introduce crystallographic methods to explore the role of organic cations in lead halide perovskites, and combine automation and Bayesian optimization to rapidly identify desired alloy compositions achieving over 40× improvement in environmental stability. In the second part of the talk, I will discuss the structural-property relationships of novel lead-free semiconductors, where a neural network accelerated the classification of X-ray diffraction patterns by 10×, enhancing our understanding of the composition-dependent bangap bowing behaviour that I discovered in a new inorganic alloy series. These findings demonstrate the power of “science + data” integrated approaches for materials discovery, and shed light on the design principles of hybrid organic-inorganic materials, pushing next-generation semiconductors closer to mass manufacturing in fighting the global energy and environmental crises.
Biography:
Dr. Shijing Sun is a research scientist at MIT Photovoltaics Research Laboratory working with Professor Tonio Buonassisi. She is the head of the Accelerated Materials Development team, developing next-generation semiconductors for renewable energy applications. Dr. Sun's research interests include materials discovery, automated experimentation, integration of solid-state chemistry with data-driven approaches, and advanced characterization using synchrotron facilities. Dr. Sun was a Total-MIT Energy Fellow in 2017-2019 for her postdoctoral research, where she focused on search criteria and thin-film fabrication routes for eco-friendly solar cells. Dr. Sun studied materials chemistry at Trinity College, University of Cambridge, U.K. under the supervision of Professor Sir Anthony Cheetham. Her PhD focused on the crystal growth, characterization, and physical properties of functional organic-inorganic hybrid materials.
