Frequency Domain Characterization of Optically Controlled Processes in Perovskite Materials

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15028
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Kyushu University
• Principal Investigator: Klotz Dino 九州大学, カーボンニュートラル・エネルギー国際研究所, 助教 (00814849)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: opto-ionics / ionic conductivity / light effect / grain boundaries / impedance

Outline of Final Research Achievements

In this project, we focused on light interaction of perovskite materials. One part of the results was establishing a detailed perspective that deconvoluted the impedance response of perovskite solar cells. The other part of the project was the discovery of an opto-ionic effect happening at grain boundaries of ionic conductors, such as perovskite materials. The experiments for this part were performed on 3%Gd-dopedCeO2 (GDC, one of the most prominent ionic conductors and model material for ionic conduction). The new opto-ionic effect immensely increases the ionic conductivity of the grain boundaries of polycrystalline materials, one of the major drawbacks for ionic conduction in technical materials. It could be shown that the space-charge region and the potential barrier caused by those can be mitigated by light above the bandgap. Photogenerated electron-hole pairs compensate the space-charges but do not lead to electronic conductivity.

Free Research Field

fuel cells

Academic Significance and Societal Importance of the Research Achievements

The discovered light effect that increases ionic conductivity could be beneficial for fuel cells, batteries, sensors and other devices that rely on ionic conductivity. It could lead to higher efficiency which will decrease energy demand and help meeting carbon emission reduction goals.