This webinar is presented by Dr. Francesca Toma and Dr. Johanna Eichhorn from Lawrence Berkeley National Laboratory (LBNL). They are pioneers in characterizing charge carrier transport in energy materials by pc-AFM.
In this webinar, Dr. Francesca Toma will give a short overview of the ongoing research projects on solar energy conversion in her group. Dr. Johanna Eichhorn will then focus on the nanoscale characterization of BiVO4 – a highly interesting semiconductor light absorber for solar water splitting. Toma and Eichhorn recently performed quantitative analysis of sub-pA photocurrent maps and IV-curves obtained with their Dimension Icon AFM. Specifically, they revealed the critical impact of (i) contact formation between the nanoscale probe and the semiconductor, and of (ii) chemical environment on nanoscale transport measurements of PEC devices. For the first time, they showed that the charge transport in BiVO4 photoanodes can be described by the space-charge-limited current model in the presence of trap states. Furthermore, they used complementary pc-AFM and in-situ Kelvin probe measurements to elucidate the influence of chemical interactions of adsorbed oxygen and water on charge transport and interfacial charge transfer of photogenerated charge carriers. Their research revealed that surface-adsorbed oxygen acts as a shallow trap state limiting electronic performance of BiVO4 thin films. Learn more and register.

SANTA BARBARA, California – November 28, 2018 – Bruker today announced the release of the Dimension XR™ family of scanning probe microscopes (SPMs). These new systems incorporate major AFM innovations, including Bruker’s proprietary and exclusive DataCube nanoelectrical modes, AFM-SECM for energy research, and the new AFM-nDMA mode, which for the first time correlates polymer nanomechanics to bulk dynamic mechanical analysis (DMA). Building on two of the world’s most utilized AFM platforms in scientific publications, the Icon® and FastScan®Dimension XR SPMs are available in three configurations optimized for nanomechanics, nanoelectrical, and nanoelectrochemical applications. These systems significantly expand researchers’ ability to quantify material properties at the nanoscale in air, fluids, electrical, and chemically reactive environments.

“The new Dimension XR systems are the culmination of years of innovations to provide quantitative and easy-to-use nanomechanical, nanoelectrical, and nanoelectrochemical characterization,” explained David V. Rossi, Executive Vice President and General Manager of Bruker’s AFM business. “Our goal is to make these first and only capabilities widely available to the research community, enabling their breakthrough AFM discoveries with new nanoscale information.”

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In this joint webinar, Dr. Teddy Huang from Bruker will first review recent AFM applications for solar fuels research (converting sunlight, water, and carbon dioxide into hydrogen and liquid fuels), covering the intrinsic challenges resulting from both the complexity of materials/device characterization and the limitation from general small-sample AFMs, and introducing the recent progress in finding solutions.

In the main part of the webinar, Prof. Fengtao Fan will introduce spatially-resolved surface photovoltage (SPV) microscopy, a five-year technical and applications development in his lab based on a Bruker Dimension Icon AFM. This KPFM-based SPV technique has been used for imaging the transfer dynamics of photocarriers generated by absorbing sunlight, providing fundamental insights and practical guidelines for device designs. Prof Fan will take the popular semiconductor metal oxide photoanodes BiVO4 and TiO2 as examples to demonstrate recent important applications of the SPV microscopic technique in advancing the solar fuels research.

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In Operando Surface Potential Sensing of Photo-electrochemical Anodes

July 25, 2018 ─ Get the latest solar water splitting research from the Boettcher group at University of Oregon, as well as Bruker’s recent Nanoelectrode probe and Data Cube developments. We start with interfacial charge transfer at the semiconductor-catalyst interface – an issue that is central for solar water splitting yet has been poorly understood. New insights require unique experimental approaches- such as using a nanoelectrode AFM-SECM probe, scanning the surface of at water splitting photoanode, and making local surface potential measurements, in operando. In this presentation, we will discuss fundamental aspects and capabilities of the probes used.

We then show how the technique allows for measurement of the surface potential and thickness-dependent electronic properties of cobalt (oxy)hydroxide phosphate (CoPi). We show that when CoPi is deposited on illuminated photoanodes like hematite (a-Fe2O3), it acts as both a hole collector and an oxygen evolution catalyst. The versatility of the technique is highlighted by comparing surface potentials of CoPi-decorated hematite and bismuth vanadate photoelectrodes. Watch the webinar.

7-18-2014 3-15-38 PM

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Nanomechanical Properties of Cell Surfaces With increasingly rapid advancements in bioresearch, there is a growing need for methods that can accurately quantify and map the molecular interactions of biological samples, both with high-force sensitivity and high spatial resolution. Force-distance (FD) curve-based atomic force microscopy is a valuable tool to simultaneously contour the surface and map the biophysical properties of biological samples at the nanoscale.

In this webinar, we will discuss the use of Bruker’s advanced FD-based technology, PeakForce QNM®, combined with chemically functionalized tips to probe the localization and interactions of chemical and biological sites on single native proteins and on living cells at high-resolution.

First, we’ll demonstrate the ability of the method to quantify and image hydrophobic forces on organic surfaces and on microbial pathogens. Then, using biochemically sensitive tips, we will detect single sensor proteins on yeast cells, locate specific interaction sites on native protein, and image filamentous bacteriophages extruding from living bacteria at unprecedented resolution. Topography and specific adhesion maps then can be analyzed and correlated either by Bruker’s NanoScope® analysis software tool or Matlab statistical software.

Owing to its key capabilities (quantitative mapping, resolution of a few nanometers, and true correlation with topography), this novel biochemically-sensitive imaging technique, based on PeakForce Tapping® technology, is a powerful complement to other advanced AFM modes for quantitative, high-resolution bio-imaging.

7-18-2014 3-12-11 PM

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Real-time control of the peak force of the tip-sample interaction with PeakForce Tapping has led to a fundamental change in atomic force microscopy (AFM), providing quantitative mapping of mechanical properties of soft materials at unprecedented resolution and speed while preserving the tip and sample. Force Volume, PeakForce Tapping and Contact Resonance (CR-AFM) can provide complimentary mechanical property information, covering a wide range of time-scales (seconds to microseconds) and accessing different properties and/or different ranges of properties. For example, PeakForce QNM and Force Volume work well with samples of modulus in the range of kPa up to a few tens of GPa, while CR-AFM can cover the range of a few GPa to hundreds of GPa. In some cases, the techniques can be combined for simultaneous results and improved stability.

In this talk, we will discuss improvements to the contact geometry analysis for CR-AFM with examples on various materials. We will also examine new developments combining CR-AFM with force-controlled modes such as force volume and PeakForce tapping. This provides new insights for contact mechanics and also into the mechanics of contact formation and contact breaking. Finally, we will consider the effect of the time dependence of material properties on all of the measurements.

About Bruker AFM Probes

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In this webinar we take a look at the growth of Peak Force Tapping in AFM research and review some of the key publications in a wide range of fields that have made use of Peak Force Tapping. Topics range over material property mapping at the nanoscale in the fields of materials, high resolution imaging, bimolecular and cell biology, batteries, graphene, organic photovoltaic, etc. Attendees will also receive a link where they can download a citation list of key publications that can be imported into popular bibliography management software packages.

When performing an AFM measurement one of the most important decisions made is the selection of the proper probe. This decision can make the difference between groundbreaking results or hours of lost time-to-data. When making a probe selection, one is faced with a cornucopia of options and this decision may feel daunting.

In this webinar, the information and probe knowledge used by AFM experts to select a probe is presented.
This webinar will begin with the role of the probe in an AFM measurement; covering the fundamentals of an AFM probe such as cantilever stiffness and frequency, probe shape and probe material and coatings. This is then followed by an in-depth, application specific presentation of probes for common experiments. Topics covered include probes for high resolution and high speed imaging; biological AFM, electrical AFM, nanomechanical AFM and Tip Enhanced Raman (TERS). Lastly, several methods for probe cleaning will be discussed. The webinar closes with a review of the Bruker AFM Probes website and probe selection guide.

This webinar explains how the AFM probe’s key specifications effect its performance, and determine its suitability for a particular application. With this tutorial you will be able to better select any AFM probe as well as make better decisions on how to optimize your experiment through the probe characteristics. Basic and advanced issues will be addressed in this fun and informative webinar.