Publication date: 10th April 2024
Low-temperature growth with mild annealing to induce crystallinity is emerging as a route to exceptional catalytic activity in mixed ionic/electronic conducting oxides (MIECs) within a limited thermal budget. While our prior work focused on the key role of electronic conductivity enhancements during crystallization and the pristine surface chemistry in promoting surface charge transfer, little is known about the ionic conductivity of amorphous MIECs nor about its evolution during crystallization. In this work we developed a thin-film cell architecture involving blocking electrodes and capping layers to quantify ionic and electronic conductivities plus ionic transference numbers at each stage of crystallization, both isothermally and during thermal excursions. Using a (La,Sr)(Ga,Fe)O3-x perovskite as a model system, we observed a ~2 orders of magnitude increase in ionic conductivity during crystallization. However, the total conductivity increased ~4 orders of magnitude. As a result, the material transitioned from being nearly a pure ionic conductor to nearly pure electronic conductor as crystallinity varied. Transference numbers over almost the full range from ~0 to ~1 could be dialed in without changing the nominal composition. By combining ac-impedance spectroscopy with simultaneous synchrotron grazing-incidence X-ray diffraction, dc polarization studies, TEM imaging, optical properties, and molecular dynamics simulations, we were able to evaluate the relative roles of lattice order and strain, defect chemistry, and microstructure in the evolving transport behavior with crystallinity.
This work is primarily funded by the Department of Energy, Basic Energy Sciences, Early Career grant DE-SC-0018963.
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.