Publication date: 10th April 2024
Ionic defects are essential building blocks for properties of complex oxides, including mixed ionic and electronic conductivity, surface kinetics and reactivity, lattice expansion and dynamics, which are important for applications ranging from energy (e.g., fuel cells and electrocatalysts) to information (e.g., memristors, neuromorphic computing devices). In this talk, I am going to cover two fronts of harnessing ionic defects for tailed oxide thin film properties. Firstly, to accurately predict electrochemical driving force needed for manipulating ionic defects for designed properties, constructing phase diagrams that correlates physical properties (conductivity, (chemical) diffusivity, lattice constant, etc.) and ionic defect concentration is essential. However, such tasks often require a large number of samples and can be susceptible to artefacts introduced by sample-to-sample variations. To tackle this challenge, we have developed a new electrochemical device that can introduce spatially-graded ionic defect concentrations in one single oxide thin film sample. Combined with materials characterization tools with high spatial resolution, we achieved high-throughput construction of phase diagrams controlled by ionic defect concentration [1,2]. Secondly, we established a comprehensive theoretical framework to understand the pivotal role of ionic defects (e.g., oxygen vacancies) in determining the activity of oxide electrocatalysts for both high-temperature [3] (>500°C, solid/gas interfaces) and low-temperature [4] (<100°C, solid/liquid interfaces) oxygen evolution reactions (OER). We found that, in both scenarios, alterations in ionic defect concentrations contribute significantly to what we refer to as “chemical overpotential”, which represents a substantial portion of the total overpotential. Overall, our work provides a holistic understanding of both “static” and “dynamic” effect of ionic defects in determining the properties and functionality of oxide thin films.
[1] H. Chen, Q. Lu* et al., Nano Letters, 22 (2022), 8983-8990
[2] Y. Lu, Q. Lu* et al., ACS Nano, 17 (2023), 14005−14013
[3] K. Yang, Q. Lu* et al., JACS 145 (2023), 25806–25814
[4] Y. Hu, Q. Lu* et al., in prep.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.