| Project/Area Number |
19K05637
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 35030:Organic functional materials-related
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
Dani Keshav 沖縄科学技術大学院大学, フェムト秒分光法ユニット, 准教授 (80630946)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2021: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2020: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2019: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | Time-resolved / photoemission / microscopy / perovskite / photovoltaics / ultrafast / dynamics / Perovskite / photovoltaic films / time-resolved / electron microscopy / time-resolved PEEM / perovskite photovoltaics / ultrafast dynamics / PEEM |
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| Outline of Research at the Start |
I propose to image the nanoscale distribution of defect sites in perovskite photovoltaic films, and to study their electronic structure and related trapping dynamics.
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| Outline of Final Research Achievements |
Over the past decade, perovskite photovoltaic materials have become the leading contenders for solar devices. Yet, the presence of defects has limited device performance. Understanding the nature of the defect states and their impact on performance required the use of a technique with nanometer- and femtosecond-scale resolution, which are challenging to obtain simultaneously. Using our novel technique of time-resolved photoemission electron microscopy (TR-PEEM), which offers such resolutions, we succeeded in imaging the defects states and understanding the mechanism of photocarrier trapping [Nature 580, 360 (2020)]. We then identified the different types of defect states [Energy & Environ. Science 14, 6320 (2021)], and studied the role of chemical heterogeneity in these films [Nature Nanotech 17, 190 (2022)]. Recently, we showed that these defects also played a critical role in seeding degradation [Nature DOI 10.1038/s41586-022-04872-1 (2022)].
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| Academic Significance and Societal Importance of the Research Achievements |
Our work visualizes and identifies nanoscale defects, and their impact on degradation. These results contribute towards the large-scale commercialization of perovskite photovoltaic technology, which is a critical component of the global strategy to address climate change and energy sustainability.
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