Scanning x-ray excited optical luminescence of heterogeneity in halide perovskite alloys
Scanning x-ray excited optical luminescence of heterogeneity in halide perovskite alloys
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DOI：
10.1088/1361-6463/aca2b9
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
Connor J. Dolan;Deniz N. Cakan;Rishi E. Kumar;Moses Kodur;J. R. Palmer;Yanqi Luo;B. Lai;D. Fenning
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文献类型：
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作者：
Connor J. Dolan;Deniz N. Cakan;Rishi E. Kumar;Moses Kodur;J. R. Palmer;Yanqi Luo;B. Lai;D. Fenning
由于可见光探针的衍射极限分辨率和许多光活性材料对高能电子探针的剂量敏感性，在纳米尺度上理解光活性材料的光电特性往往是具有挑战性的。在这项研究中，我们展示了相关的基于同步加速器的扫描x射线激发光学发光（XEOL）和x射线荧光（XRF），以同时探测光伏和光电子器件感兴趣的卤化物钙钛矿薄膜的局部组成和光电性能。我们发现，在硬x射线照射下，钙钛矿的XEOL稳定性、发射红移和峰展宽与连续可见光激光照射下的光致发光测量趋势相关。在强烈的x射线探针照射下，XEOL的稳定性足以允许概念验证相关映射。在本研究中，典型的同步加速器XRF和纳米衍射测量使用的采集时间比XEOL扫描所用的5秒采集时间短10 - 100倍，这表明改进发光检测应该能够在最小的材料降解情况下成功地进行相关的XEOL测量。对钙钛矿下面石英衬底的XEOL发射的分析表明，它有望用作实时原位x射线剂量计，这可以为钙钛矿和其他光束敏感材料的XEOL数据收集的未来优化提供定量指标。总的来说，这些数据表明，XEOL代表了一条有希望的途径，可以提高表征纳米尺度非均质性和光学活性材料缺陷的分辨率，这可能被应用到x射线纳米探针中，以补充现有的x射线模式。
Understanding the optoelectronic properties of optically active materials at the nanoscale often proves challenging due to the diffraction-limited resolution of visible light probes and the dose sensitivity of many optically active materials to high-energy electron probes. In this study, we demonstrate correlative synchrotron-based scanning x-ray excited optical luminescence (XEOL) and x-ray fluorescence (XRF) to simultaneously probe local composition and optoelectronic properties of halide perovskite thin films of interest for photovoltaic and optoelectronic devices. We find that perovskite XEOL stability, emission redshifting, and peak broadening under hard x-ray irradiation correlates with trends seen in photoluminescence measurements under continuous visible light laser irradiation. The XEOL stability is sufficient under the intense x-ray probe irradiation to permit proof-of-concept correlative mapping. Typical synchrotron XRF and nano-diffraction measurements use acquisition times 10–100x shorter than the 5-second acquisition employed for XEOL scans in this study, suggesting that improving luminescence detection should allow correlative XEOL measurements to be performed successfully with minimal material degradation. Analysis of the XEOL emission from the quartz substrate beneath the perovskite reveals its promise for use as a real-time in-situ x-ray dosimeter, which could provide quantitative metrics for future optimization of XEOL data collection for perovskites and other beam-sensitive materials. Overall, the data suggest that XEOL represents a promising route towards improved resolution in the characterization of nanoscale heterogeneities and defects in optically active materials that may be implemented into x-ray nanoprobes to complement existing x-ray modalities.