CAREER: Understanding Light-induced Polarization in Halide Perovskites for Responsive Ferroelectrics

Nontechnical Description Hybrid perovskites are renowned for their exceptional ability to harness sunlight for applications in solar cells and optoelectronic technologies. In addition to their photovoltaic properties, certain hybrid perovskites exhibit molecular ferroelectricity—a characteristic that enables efficient charge storage and switching. This property holds significant potential to enhance the performance of solar cells and electronic devices. However, the soft and dynamic nature of their ionic lattice poses considerable challenges in understanding and precisely controlling ferroelectric behavior. In this research project, the research team aims to find new ways to control ferroelectricity in hybrid perovskites using light instead of electricity. By using light, the team will avoid problems caused by the materials’ soft structure and unwanted reactions during testing. The goal is to create materials that have stable ferroelectric properties even at room temperature. This could lead to the development of new, efficient electronic devices such as memory storage systems that use light to switch states, rather than relying on physical electrical contact. Furthermore, the PI aims to inspire and train the next generation of scientists by involving broad range of students in cutting-edge research. Through hands-on demonstrations and outreach to young learners, from preschoolers to high school students, the project will spark interest in science and technology. The project will also enable real-world applications, such as improving data storage or creating new ways to control electronic devices using light. Technical Description This project will investigate light-induced ferroelectric polarization in hybrid halide perovskites to address limitations in traditional approaches to ferroelectric characterization. Ferroelectricity in 3D lead-based hybrid perovskites (e.g., MAPbI3) is hindered by their soft ionic lattice, rapid structural dynamics, and unwanted ionic effects near interfaces during electric-field-based measurements. Instead, the PI will explore a hypothesis that an optically induced electric field can avoid these issues and allow precise control over crystal structure polarization, paving the way for enhanced dynamic lattice distortion critical for generating ferroelectric polarization. The approach combines novel materials design with advanced spectroscopy tools to uncover metastable polar phases in halide perovskites, stabilizing them at ambient conditions. These transient non-equilibrium polar states, typically absent from phase diagrams, offer opportunities for non-contact manipulation of ferroelectric domains using light. By bridging the gap between transient and long-lived polar phases, the research team will aim to unlock their potential for functional ferroelectric, ferromagnetic, and multiferroic applications. This five-year project will focus on probing light-matter interactions in soft dielectric halide perovskites. By stabilizing metastable polar phases and understanding their dynamics, the team will aim to advance the fundamental knowledge of ferroelectric and multiferroic phenomena in these materials system, addressing key challenges in achieving long-lived, stable polarization states under ambient conditions. Additionally, the project will emphasize broadening participation in STEM, offering mentorship and training opportunities to students, and engaging young learners through outreach initiatives to inspire the next generation of innovators. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.