We greatly acknowledge J. Garrevoet, M. Seyrich, A. Schropp, D. Br&#252;ckner, J. Hagemann, K. Spiers, and T. Boese from the Deutsches Elektronen-Synchrotron (DESY) and A. Kolditz, J. Siebels, J. Fl&#252;gge, C. Strelow, T. Kipp, and A. Mews from the University of Hamburg for supporting measurements at beamline P06 at PETRA III, DESY; M. Holt, Z. Cai, M. Cherukara, and V. Rose from the Argonne National Laboratory (ANL) for supporting measurements at beamline 26-ID-C at the Advanced Photon Source (APS) at ANL; D. Salomon and R. Tucoulou from the European Synchrotron Radiation Facility (ESRF) for supporting measurements at beamline ID16B at ESRF; R. Farshchi, D. Poplavkyy, and J. Bailey from MiaSol&#233; Hi-Tech Corp., and E. Avancini, Y. Romanyuk, S. B&#252;cheler, and A. Tiwari from the Swiss Federal Laboratories for Materials Science and Technology (EMPA) for providing solar cells. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. We acknowledge the European Synchrotron Radiation Facility (Grenoble, France) for provision of synchrotron radiation facilities. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

The authors have nothing to disclose.

An erratum was issued for: <a href="https://www-jove-com.remotexs.ntu.edu.sg/t/60001/x-ray-beam-induced-current-measurements-for-multi-modal-x-ray">X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells</a>. An equation&#160;was&#160;updated.
Equation 9&#160;was updated from:
<img alt="Equation" src="/files/ftp_upload/60001/60001eq58v5.jpg" />
to:
<img alt="Equation" src="/files/ftp_upload/60001/60001eq58v9.png" />

An erratum was issued for: <a href="https://www-jove-com.remotexs.ntu.edu.sg/t/60001/x-ray-beam-induced-current-measurements-for-multi-modal-x-ray">X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells</a>. An equation&#160;was&#160;updated.

Erratum: X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

In a world where the demand for electrical energy is constantly rising, a clean and sustainable energy source is increasingly necessary. One possibility to tackle these demands are photovoltaic (PV) systems1,2,3. For a directed and efficient way of developing next-generation solar cells, it is necessary to understand how the composition and structure of the solar cells affect their performance4. Typical questions in solar cell development include: Which types of defects are most detrimental, and where are they located5,6? Are there inhomogeneities in the elemental distribution, and what is their impact7,8,9? How do the solar cells change upon module assembly and aging10,11?
As a solar cell is only as good as its weakest part, it is especially important to understand the effect of compositional and structural variation on the performance in polycrystalline solar cells that suffer inherently from inhomogeneities7,8. This is particularly true for thin film (TF) solar cells, which contain absorber layers with crystallite sizes in the micrometer range. Here, the effect of grain boundaries on performance is of highest interest, but their small size and the fact that they are buried in an entire layer stack pose unique characterization challenges. Furthermore, the complex chemistry of multi-component absorber layers with co-existing phases and internal gradients require sophisticated characterization methods12.
Synchrotron-based hard X-ray microscopes are able to meet the characterization challenges of TF solar cells: they provide X-ray spot sizes down to the nanometer scale13,14,15,16 and the penetration depth of hard X-rays allows to probe the different device layers17, including buried absorber layers. With a wealth of different measurement techniques at a scanning X-ray microscope, it becomes possible to simultaneously study not just one, but many different aspects of solar cells within multi-modal measurements and to correlate the observed characteristics. For example, X-ray beam induced current (XBIC) measurements have successfully been combined with X-ray fluorescence (XRF)7,18,19, X-ray excited optical luminescence (XEOL)20,21, and X-ray diffraction (XRD)22 to correlate the electrical performance with composition, optical performance, and structure, respectively23.
During XBIC measurements of solar cells or other devices under test (DUT)24,25, the incident X-ray photons set off particle showers consisting of electrons and photons, resulting in a multitude of excited electron-hole pairs per incident X-ray photon in the semiconducting absorber material. Finally, the electron-hole pairs thermalize to the band edges of the solar cell absorber. Therefore, these X-ray excited charge carriers can be treated like charge carriers that are generated by the absorption of photons with energies just above the bandgap during normal solar cell operation, and the resulting current or voltage can be measured as X-ray beam induced current23,26,27 or voltage (XBIV)28,29 similar to more common measurements like electron-beam induced current (EBIC) or laser-beam induced current (LBIC). Consequently, the XBIC/XBIV signal not only depends on the thickness of the absorber layer, but also on the electric performance of the DUT, both at the microscopic and macroscopic level, including the local bandgap, Fermi-level splitting, and recombination. Thus, we are able to map local variations of the charge-carrier collection efficiency that is defined as the probability that an externally excited electron-hole pair in the absorber layer is collected at the electrical contacts of the DUT.
Note that only electron-hole pairs that are generated in the absorber layer of the DUT contribute to the XBIC/XBIV signal. Charge carriers generated in other layers such as the metallic contacts or substrate will immediately recombine, as they have no possibility of being separated by the junction. Therefore, other layers only affect XBIC/XBIV measurements via secondary effects such as parasitic X-ray absorption or the emission of secondary photons and electrons that may be re-absorbed in the absorber layer. In contrast, all layers potentially contribute to the XRF signal.
Given that the XBIC and XBIV signals can be small (often, variations in the sub-picoampere and nanovolt range are of interest), the signals are easily buried in noise. Therefore, we suggested to utilize lock-in amplification to extract the XBIC and XBIV signals30. For this purpose, the incoming X-ray beam is modulated by an optical chopper as indicated in Figure&#160;1. This modulation carries over to the signal produced by the DUT. Before the signal is fed into the lock-in amplifier (LIA), a pre-amplifier (PA) is typically used to match the raw signal intensity with the range of the analog-to-digital converter at the input of the digital LIA. The LIA mixes the modulated measurement signal with the reference signal. By employing a low-pass filter, only frequencies close to the reference signal are passed through and amplified31. This allows for an effective extraction of the XBIC or XBIV signal from a noisy background.
In the protocol, we introduce the prerequisites and motions necessary for taking successful XBIC measurements including the raw signal (direct current, DC) and the modulated signal (alternating current, AC). Beyond describing technical details, we discuss an XBIC setup in the context of multi-modal measurements at beamline P06 at PETRA III13. Please note that, compared to most laboratory experiments, the environment of hutches at hard X-ray nanoprobes requires particular planning and consideration. Specifically, multi-modal measurements with nanometer-scale resolution challenge the experimentalists with a variety of specific constraints. For example, electronic noise is often present with great amplitudes from piezo-driven motors and other equipment, such as the power supplies of detectors. Furthermore, a multitude of devices and detectors needs to be arranged at optimized geometry without interfering with each other nor inducing vibrations. Figure&#160;1 depicts a typical setup for XBIC measurements in combination with XRF and small/wide angle X-ray scattering (SAXS/WAXS) measurements.

<table><tbody><tr><td>BNC cabling and connectors</td><td></td><td></td><td>From generall cable suppliers</td></tr><tr><td>Chopper blade</td><td>Thorlabs</td><td>MC1F10HP</td><td>Apart from technical compatibility of the chopper wheel with the chopper system, it should be checked that the chopper blade sufficiently blocks the X-ray beam.</td></tr><tr><td>Conductive silver paint</td><td>Conrad</td><td>530042</td><td>Alternative products can be obtained from Pelco and others</td></tr><tr><td>Copper wires</td><td></td><td></td><td>From cable suppliers for contacting of the solar cell</td></tr><tr><td>Current Preamplifier</td><td>Standford</td><td>SR570</td><td>Alternatives include the Keithley 487 or 6487 Picoammeter.&amp;nbsp;</td></tr><tr><td>Device under test (DUT)</td><td></td><td></td><td>Suitable device for XBIC measurements.</td></tr><tr><td>Holder with printed circuit board</td><td></td><td></td><td>Custom design</td></tr><tr><td>Kinematic sample mount</td><td>Thorlabs</td><td>KB25/M</td><td>Optional, allows easy positioning and changing of sample. Alternatives include the M-BK-1A from Newport</td></tr><tr><td>Lock-in Amplifier</td><td>Zurich Instruments</td><td>UHFLI or MFLI</td><td>Whereas the MFLI has current preamplifiers included, the UHFLI requires an external current preamplifier but offers more options. Therefore, the UHFLI was used for the presented experiment.</td></tr><tr><td>Measurement control/data acquisition unit</td><td></td><td></td><td>Available at different synchrotrons.</td></tr><tr><td>Optical Chopper</td><td>Thorlabs</td><td>MC2000B(-EC)</td><td>Alternatives include the choppers SR540 from Stanford Research Systems, or model 3502 from Newport.</td></tr><tr><td>Polyimide tape</td><td></td><td></td><td>Rolls with different widths and thicknesses are available</td></tr><tr><td>X-ray source</td><td></td><td></td><td>Available at different synchrotrons</td></tr></tbody></table>

x-ray beam induced current measurements for multi-modal x-ray microscopy of solar cells

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is employed simultaneously with other techniques within a multi-modal X-ray microscopy approach. An example is given herein combining XBIC with X-ray fluorescence to enable point-by-point correlations of the electrical performance with chemical composition. For the highest signal-to-noise ratio in XBIC measurements, lock-in amplification plays a crucial role. By this approach, the X-ray beam is modulated by an optical chopper upstream of the sample. The modulated X-ray beam induced electrical signal is amplified and demodulated to the chopper frequency using a lock-in amplifier. By optimizing low-pass filter settings, modulation frequency, and amplification amplitudes, noise can efficiently be suppressed for the extraction of a clear XBIC signal. A similar setup can be used to measure the X-ray beam induced voltage (XBIV). Beyond standard XBIC/XBIV measurements, XBIC can be measured with bias light or bias voltage applied such that outdoor working conditions of solar cells can be reproduced during in-situ and operando measurements. Ultimately, the multi-modal and multi-dimensional evaluation of electronic devices at the nanoscale enables new insights into the complex dependencies between composition, structure, and performance, which is an important step towards solving the materials&#39; paradigm.

Watch this Scientific Journal Video about X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells at JoVE.com

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

A setup for X-ray beam induced current measurements at synchrotron beamlines is described. It unveils the nanoscale performance of solar cells and extends the suite of techniques for multi-modal X-ray microscopy. From wiring to signal-to-noise optimization, it is shown how to perform state-of-the-art XBIC measurements at a hard X-ray microprobe.

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is ...

x-ray-beam-induced-current-measurements-for-multi-modal-x-ray

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13.7K Views.  Deutsches Elektronen-Synchrotron. Röntgenfoto's veroorzaken een stroom in veel elektronische apparaten. Heel erg als zichtbare fotonen in fotovoltaïsche zonnecellen. Het signaal wordt x-ray beam geïnduceerde stroom genoemd.Met andere woorden, de testapparaten worden bediend als röntgendetectoren en XBIC levert de prestaties van het lokale apparaat op. XBIC combineert de hoge speciale resolutie van elektronenbundel-geïnduceerde stroom met een hoge penetratiediepte van laserstraal geïnduceerde stroom. Deze combinat...

Video: X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

Concurrent Quantitative Conductivity and Mechanical Properties Measurements of Organic Photovoltaic Materials using AFM

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. Thus, understanding of spatial variations in composition as well as electrical properties of OPV materials is of paramount importance for moving PV technology forward.1,2 In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution. Currently, materials properties measurements performed using commercially available AFM-based techniques (PeakForce, conductive AFM) generally provide only qualitative information. The values for resistance as well as Young's modulus measured using our method on the prototypical ITO/PEDOT:PSS/P3HT:PC61BM system correspond well with literature data. The P3HT:PC61BM blend separates onto PC61BM-rich and P3HT-rich domains. Mechanical properties of PC61BM-rich and P3HT-rich domains are different, which allows for domain attribution on the surface of the film. Importantly, combining mechanical and electrical data allows for correlation of the domain structure on the surface of the film with electrical properties variation measured through the thickness of the film.

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.

Organic photovoltaic  (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale  inhomogeneity of OPV materials affects performance ...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM)

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography CT and Light Microscopy LM Correlated with Scanning Electron Microscopy SEM

A workflow for comprehensive micro-characterization of active optical devices is outlined. It contains structural as well as functional investigations by means of CT, LM and SEM. The method is demonstrated for a white LED which can be still be operated during characterization.

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of ...

Quantifying X-Ray Fluorescence Data Using MAPS

The quantification of X-ray fluorescence (XRF) microscopy maps by fitting the raw spectra to a known standard is crucial for evaluating chemical composition and elemental distribution within a material. Synchrotron-based XRF has become an integral characterization technique for a variety of research topics, particularly due to its non-destructive nature and its high sensitivity. Today, synchrotrons can acquire fluorescence data at spatial resolutions well below a micron, allowing for the evaluation of compositional variations at the nanoscale. Through proper quantification, it is then possible to obtain an in-depth, high-resolution understanding of elemental segregation, stoichiometric relationships, and clustering behavior.
This article explains how to use the MAPS fitting software developed by Argonne National Laboratory for the quantification of full 2-D XRF maps. We use as an example results from a Cu(In,Ga)Se2 solar cell, taken at the Advanced Photon Source beamline 2-ID-D at Argonne National Laboratory. We show the standard procedure for fitting raw data, demonstrate how to evaluate the quality of a fit and present the typical outputs generated by the program. In addition, we discuss in this manuscript certain software limitations and offer suggestions for how to further correct the data to be numerically accurate and representative of spatially resolved, elemental concentrations.

Here, we demonstrate the use of the X-ray fluorescence fitting software, MAPS, created by Argonne National Laboratory for the quantification of fluorescence microscopy data. The quantified data that results is useful for understanding the elemental distribution and stoichiometric ratios within a sample of interest.

The quantification of X-ray fluorescence (XRF) microscopy maps by fitting the raw spectra to a known standard is crucial for evaluating chemical ...

Chemistry

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass (ADG) Fresnel Lens for Concentrating Photovoltaics

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is composed of two materials, a plastic and an elastomer, whose dispersion characteristics (refractive index variation with wavelength) are different. We first designed the lens geometry and then used ray-tracing simulation, based on the Monte Carlo method, to analyze its performance from the point of view of both optical efficiency and the maximum attainable concentration. Afterwards, ADG Fresnel lens prototypes were manufactured using a simple and reliable method. It consists of a prior injection of plastic parts and a consecutive lamination, together with the elastomer and a glass substrate to fabricate the parquet of ADG Fresnel lenses. The accuracy of the manufactured lens profile is examined using an optical microscope while its optical performance is evaluated using a solar simulator for concentrator photovoltaic systems. The simulator is composed of a xenon flash lamp whose emitted light is reflected by a parabolic mirror. The collimated light has a spectral distribution and an angular aperture similar to the real Sun. We were able to assess the optical performance of the ADG Fresnel lenses by taking photographs of the irradiance spot cast by the lens using a charge-coupled device (CCD) camera and measuring the photocurrent generated by several types of multi junction (MJ) solar cells, which have been previously characterized at a solar simulator for concentrator solar cells. These measurements have demonstrated the achromatic behavior of ADG Fresnel lenses and, as a consequence, the suitability of the modelling and manufacturing methods.

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

The achromatic doublet on glass (ADG) Fresnel lens makes use of two materials with differing dispersion to reduce chromatic aberration and increase attainable concentration. In this paper, a protocol for the complete characterization of the ADG Fresnel lens is presented.

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is ...

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid based on volatile solar and wind sources. The pressing demand of developing high-performance electrochemical energy storage solutions, i.e., batteries, relies on both fundamental understanding and practical developments from both the academy and industry. The formidable challenge of developing successful battery technology stems from the different requirements for different energy-storage applications. Energy density, power, stability, safety, and cost parameters all have to be balanced in batteries to meet the requirements of different applications. Therefore, multiple battery technologies based on different materials and mechanisms need to be developed and optimized. Incisive tools that could directly probe the chemical reactions in various battery materials are becoming critical to advance the field beyond its conventional trial-and-error approach. Here, we present detailed protocols for soft X-ray absorption spectroscopy (sXAS), soft X-ray emission spectroscopy (sXES), and resonant inelastic X-ray scattering (RIXS) experiments, which are inherently elemental-sensitive probes of the transition-metal 3d and anion 2p states in battery compounds. We provide the details on the experimental techniques and demonstrations revealing the key chemical states in battery materials through these soft X-ray spectroscopy techniques.

Here, we present a protocol for typical experiments of soft X-ray absorption spectroscopy (sXAS) and resonant inelastic X-ray scattering (RIXS) with applications in battery material studies.

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

Sample Preparation and Experimental Design for In Situ Multi-Beam Transmission Electron Microscopy Irradiation Experiments

There is a need to understand materials exposed to overlapping extreme environments such as high temperature, radiation, or mechanical stress. When these stressors are combined there may be synergistic effects that enable unique microstructural evolution mechanisms to activate. Understanding of these mechanisms is necessary for the input and refinement of predictive models and critical for engineering of next generation materials. The basic physics and underlying mechanisms require advanced tools to be investigated. The in situ ion irradiation transmission electron microscope (I&#179;TEM) is designed to explore these principles.
To quantitatively probe the complex dynamic interactions in materials, careful preparation of samples and consideration of experimental design is required. Particular handling or preparation of samples can easily introduce damage or features that obfuscate the measurements. There is no one correct way to prepare a sample; however, many mistakes can be made. The most common errors and things to consider are highlighted within. The I&#179;TEM has many adjustable variables and a large potential experimental space, therefore it is best to design experiments with a specific scientific question or questions in mind.
Experiments have been performed on large number of sample geometries, material classes, and with many irradiation conditions. The following are a subset of examples that demonstrate unique in situ capabilities utilizing the I3TEM. Au nanoparticles prepared by drop casting have been used to investigate the effects of single ion strikes. Au thin films have been used in studies on the effects of multibeam irradiation on microstructure evolution. Zr films have been exposed to irradiation and mechanical tension to examine creep. Ag nanopillars were subjected to simultaneous high temperature, mechanical compression, and ion irradiation to study irradiation induced creep as well. These results impact fields including: structural materials, nuclear energy, energy storage, catalysis, and microelectronics in space environments.

Sample preparation techniques are outlined with specific considerations for in situ ion irradiation TEM experiments. Ion species, energy, and fluence are discussed with methods for how to select and compute them. Finally, procedures for conducting an experiment are described and accompanied by the representative results.

There is a need to understand materials exposed to overlapping extreme environments such as high temperature, radiation, or mechanical stress. When these ...

In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation

We present an in-house, in situ Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiment, developed to probe the drying kinetics of roll-to-roll slot-die coating of the active layer in organic photovoltaics (OPVs), during deposition. For this demonstration, the focus is on the combination of P3HT:O-IDTBR and P3HT:EH-IDTBR, which have different drying kinetics and device performance, despite their chemical structure only varying slightly by the sidechain of the small molecule acceptor. This article provides a step-by-step guide to perform an in situ GISAXS experiment and demonstrates how to analyze and interpret the results. Usually, performing this type of in situ X-ray experiments to investigate the drying kinetics of the active layer in OPVs relies on access to synchrotrons. However, by using and further developing the method described in this paper, it is possible to perform experiments with a coarse temporal and spatial resolution, on a day-to-day basis to gain fundamental insight in the morphology of drying inks.

This paper is a demonstration and a guideline to perform and analyze in-house (with a laboratory X-ray instrument) in situ GISAXS experiments of drying inks on roll-to-roll slot-die coated, non-fullerene organic photovoltaics.

We present an in-house, in situ Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiment, developed to probe the drying kinetics of roll-to-roll ...

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

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