Quantifying X-Ray Fluorescence Data Using MAPS

Nietzold, Tara; West, Bradley; Stückelberger, Michael; Lai, Barry; Vogt, Stefan; Bertoni, Mariana I.

doi:10.3791/56042

Cited by 23 publications

(25 citation statements)

References 19 publications

(12 reference statements)

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“…The emitted radiation is then analyzed by either photon energy or wavelength. To determine the concentration of each element in the scanned tissue, the intensity of the characteristic radiation is compared to a known standard scanned at the beginning and end of each session (Nietzold et al, 2018). To obtain a high-resolution map of elements and their concentrations within the target tissue, an x-ray beam with a small spot size is rastered across the tissue.…”

Section: X-ray Fluorescence Microscopy (Xfm)mentioning

confidence: 99%

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X-ray fluorescence microscopy: A method of measuring ion concentrations in the ear

et al. 2020

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This technical note describes synchrotron x-ray fluorescence microscopy (XFM) as a method for measuring the concentrations of different elements in cross-sections of the ear at extremely high resolution. This method could be of great importance for addressing many open questions in hearing research. XFM uses synchrotron radiation to evoke emissions from many biologically relevant elements in the tissue. The intensity and wavelength of the emitted radiation provide a fingerprint of the tissue composition that can be used to measure the concentration of the elements in the sampled location. Here, we focus on energies that target biologically-relevant elements of the periodic table between magnesium and zinc. Since a highly focused x-ray beam is used, the spot size is well below 1 mm and the samples can be scanned at a nanometer lateral resolution. This study shows that measurement of the concentrations of different elements is possible in a mid-modiolar cross-section of a mouse cochlea. Images are presented that indicate potassium and chloride "hot spots" in the spiral ligament and the spiral limbus, providing experimental evidence for the potassium recycling pathway and showing the cochlear structures involved. Scans of a section obtained from the incus, one of the middle ear ossicles, in a developing mouse have shown that zinc is not uniformly distributed This supports the hypothesis that zinc plays a special role in the process of ossification. Although limited by sophisticated sample preparation and sectioning, the method provides ample exciting opportunities, to understand the role of genetics and epigenetics on hearing mechanisms in ontogeny and phylogeny.

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Section: X-ray Fluorescence Microscopy (Xfm)mentioning

confidence: 99%

“…Fluorescence spectra were collected with a fourelement silicon drift detector positioned at an angle of 90 to the incident x-ray beam (Vortex-EX, SII Nanotechnology, CA). Data sets were processed with MAPS software (Nietzold et al, 2018;Vogt, 2003).…”

Section: Imaging Of Samplesmentioning

confidence: 99%

X-ray fluorescence microscopy: A method of measuring ion concentrations in the ear

et al. 2020

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“…For the analysis of halide perovskite devices, we thus emphasize within‐sample analysis and comparison of samples produced using identical processes. The quantification process for nano‐XRF as applied for thin film solar cells was recently reported in detail in a visualized experiment to facilitate use by the broader community …”

Section: Tools To Assess Nanoscale Perovskite Chemistry and Its Optoementioning

confidence: 99%

The Relationship between Chemical Flexibility and Nanoscale Charge Collection in Hybrid Halide Perovskites

Luo

Aharon

Stückelberger

et al. 2018

Adv Funct Materials

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Hybrid organometal halide perovskites are known for their excellent optoelectronic functionality as well as their wide-ranging chemical flexibility. The composition of hybrid perovskite devices has trended toward increasing complexity as fine-tuned properties are pursued, including multielement mixing on the constituents A and B and halide sites. However, this tunability presents potential challenges for charge extraction in functional devices. Poor consistency and repeatability between devices may arise due to variations in composition and microstructure. Within a single device, spatial heterogeneity in composition and phase segregation may limit the device from achieving its performance potential. This review details how the nanoscale elemental distribution and charge collection in hybrid perovskite materials evolve as chemical complexity increases, highlighting recent results using nondestructive operando synchrotron-based X-ray nanoprobe techniques. The results reveal a strong link between local chemistry and charge collection that must be controlled to develop robust, high-performance hybrid perovskite materials for optoelectronic devices.applications including solar cells, [1,2] lightemitting diodes, [3] lasers, [4] and photodetectors. [5] The exceptional minority carrier diffusion lengths in these materials [6,7] lead to nearly 100% internal quantum efficiency [8] which results in high charge-carrier collection efficiency and high external luminescence efficiency in electron-photon conversion devices. [9] Particularly in the field of photovoltaics (PV), their extraordinary material properties [10][11][12] have enabled perovskite solar absorbers to achieve large improvements in device performance in the past 8 years. The perovskite crystal structure is shown in Figure 1a, where the A-site is CH 3 NH 3 + (MA, methylammonium), the B-site is Pb 2+ , and the X-site is I − following the general perovskite formula ABX 3. After demonstration of a device with 3.8% power conversion efficiency (PCE) by Miyasaka and co-workers in a dye-sensitized solar cell architecture using CH 3 NH 3 PbI 3 , [13] a breakthrough in perovskite photovoltaics occurred in 2012 when the first allsolid-state hybrid perovskite devices were shown by Kim et al., [14] improving the chemical stability of the perovskite and enabling device performance to exceed beyond 9% using CH 3 NH 3 PbI 3 perovskites. With intense investigation of perovskite material properties from research groups all over the world, including bandgap engineering by halide mixing [15,16] and device optimization using A-site mixing, [9,17] the record PCE of hybrid perovskite solar cells reached 22.7% in 2017 after achieving 22.1% PCE in 2015 [18] using a mixture of formamidinium lead iodide (CH(NH 2 ) 2 PbI 3 ) with 5% loading of methylammonium lead bromide (CH 3 NH 3 PbBr 3 ) chemistry. [19,20] Surpassing 22% PCE by leveraging the chemical flexibility of the perovskite structure brought hybrid perovskite solar cells on par in efficiency with most polycrystalline solar absor...

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“…To collect high-sensitivity XRF measurements combined with an XBIC measurement such as in the case of figure 9, we used the step-scan mode with 1 s dwell time and200 nm 200 nm step size. From the XRF spectra of the sample and thin-film references, the elemental distributions of Cu and Ga were determined using the analysis software MAPS [23,51,52]. The XRF data were corrected for self-absorption effects, as discussed in [24], with a sensitivity analysis included as well.…”

Section: Methodsmentioning

confidence: 99%

Defect activation and annihilation in CIGS solar cells: an operando x-ray microscopy study

et al. 2020

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The efficiency of thin-film solar cells with a Cu( -In x 1 Ga x )Se 2 absorber is limited by nanoscopic inhomogeneities and defects. Traditional characterization methods are challenged by the multi-scale evaluation of the performance at defects that are buried in the device structures. Multi-modal x-ray microscopy offers a unique tool-set to probe the performance in fully assembled solar cells, and to correlate the performance with composition down to the micro-and nanoscale. We applied this approach to the mapping of temperature-dependent recombination for Cu( -In x 1 Ga x )Se 2 solar cells with different absorber grain sizes, evaluating the same areas from room temperature to  100 C. It was found that poor performing areas in the large-grain sample are correlated with a Cu-deficient phase, whereas defects in the small-grain sample are not correlated with the distribution of Cu. In both samples, classes of recombination sites were identified, where defects were activated or annihilated by temperature. More generally, the methodology of combined operando and in situ x-ray microscopy was established at the physical limit of spatial resolution given by the device itself. As proof-ofprinciple, the measurement of nanoscopic current generation in a solar cell is demonstrated with applied bias voltage and bias light.

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Quantifying X-Ray Fluorescence Data Using MAPS

Cited by 23 publications

References 19 publications

X-ray fluorescence microscopy: A method of measuring ion concentrations in the ear

X-ray fluorescence microscopy: A method of measuring ion concentrations in the ear

The Relationship between Chemical Flexibility and Nanoscale Charge Collection in Hybrid Halide Perovskites

Defect activation and annihilation in CIGS solar cells: an operando x-ray microscopy study

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