Tag: atomic force microscopy

Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

In the article cited below Katherine Atamanuk, Justin Luria and Bryan D. Huey present “a new approach for directly mapping VOC (open-circuit voltage) with nanoscale resolution, requiring a single, standard-speed AFM scan. This leverages the concept of the proportional-integral-derivative (PID) feedback loop that underpins nearly all AFM topography imaging.”*

NanoWorld™ Pointprobe® CDT-NCHR conductive diamond coated silicon AFM probes were used in the described CT-AFM experiment.

Supporting information for «Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics”: Figure S1: Representative quasi-VOC* image from the measured photocurrent upon illumination during an applied voltage fixed at 700 mV. NANOSENSORS conductive diamond coated CDT-NCHR AFM probes were used in the described CT-AFM experiment
Supporting information for «Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics”: Figure S1: Representative quasi-VOC* image from the measured photocurrent upon illumination during an applied voltage fixed at 700 mV.

“Cadmium Telluride (CdTe) is an inexpensive thin-film photovoltaic with ca. 5% of the 2017 global market share for solar cells. To optimize the efficiency and reliability of these, or any electronic devices, a thorough understanding of their composition, microstructure, and performance is necessary as a function of device design, processing, and in-service conditions. Atomic force microscopy (AFM) has been a valuable tool for such characterization, especially of materials properties and device performance at the nanoscale. In the case of thin-film solar cells, local photovoltaic (PV) properties such as the open-circuit voltage, photocurrent, and work function have been demonstrated to vary by an order of magnitude, or more, within tens of nanometers […] Recently, property mapping with high spatial resolution by AFM has been further combined with the ability to serially mill a surface, in order to reveal underlying surface structures and uniquely develop three-dimensional (3D) nanoscale property maps. The most notable examples are based on pure current detection with the AFM to resolve conduction pathways in filamentary semiconducting devices and interconnects […], and tomographic AFM of photocurrents in polycrystalline solar cells during in situ illumination […].”*

*Katherine Atamanuk, Justin Luria, Bryan D. Huey
Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics
Beilstein Journal of Nanotechnology 2018, 9, 1802–1808.
doi: 10.3762/bjnano.9.171

The article cited above is part of the Thematic Series “Scanning probe microscopy for energy-related materials”.

Please follow this external link for the full article: https://www.beilstein-journals.org/bjnano/articles/9/171

The article “Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics” by Atamanuk et. al is an Open Access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Membrane sculpting by curved DNA origami scaffolds

In the article “Membrane sculpting by curved DNA origami scaffolds” the authors show that “dependent on curvature, membrane affinity and surface density, DNA origami coats can indeed reproduce the activity of membrane-sculpting proteins such as BAR, suggesting exciting perspectives for using them in bottom-up approaches towards minimal biomimetic cellular machineries.”*

The AFM images for this article were taken in high-speed AC mode using NanoWorld Ultra-Short Cantilevers of the USC-F0.3-k0.3 type.

Supplementary Figure 5 b from Membrane sculpting by curved DNA origami scaffolds: Characterization of folded DNA origami nanoscaffolds. ( a ) Assembly of the folded bare origami structures L, Q, H was initially assessed via agarose gel (2%) electrophoresis analysis. Lanes containing marker DNA ladder (1kb) and M13 single - stranded p7249 sc affold (Sc) were also included. ( b ) Structure of folded bare origami L, Q and H was further validated using negative - stain transmission electron microscopy (TEM ; scale bar s : 100 nm ) and atomic force microscopy (AFM ; scale bar s : 200nm ).
Supplementary Figure 5 b from “Membrane sculpting by curved DNA origami scaffolds”:
Characterization of folded DNA origami nanoscaffolds.
b) Structure of folded bare origami L, Q and H was further validated using negative-stain transmission electron microscopy (TEM; scale bars: 100 nm) and atomic force microscopy (AFM; scale bars: 200nm).

*Henri G. Franquelim, Alena Khmelinskaia, Jean-Philippe Sobczak, Hendrik Dietz, Petra Schwille
Membrane sculpting by curved DNA origami scaffolds
Nature Communicationsvolume 9, Article number: 811 (2018)
DOI: https://doi.org/10.1038/s41467-018-03198-9

Please follow this link to the full article: https://rdcu.be/8zZi

Open Access: The article “Membrane sculpting by curved DNA origami scaffolds” by Franquelim et. al is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit

In the article “Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit” the authors use, for the first time, phonon-polariton-resonant h-BN ribbons for SEIRA spectroscopy of small amounts of organic molecules in Fourier transform infrared spectroscopy. They demonstrate a new way to strongly couple infrared light and molecular vibrations, by utilizing phonon polariton nanoresonators made of hexagonal boron nitride, a Van der Waals material.

For the nanoscale Fourier transform infrared (nano-FTIR) spectroscopy mentioned in this article an oscillating Pt/Ir coated NanoWorld Arrow-NCPt AFM probe was illuminated by p-polarized mid-IR broadband radiation.

Figure 2 from "Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit": Far- and near-field spectroscopic characterization of h-BN ribbon arrays. (a) Sketch of the transmission spectroscopy experiment. Incoming light at normal incidence is polarized perpendicular to the ribbons to excite the HPhP resonance. (b) Transmission spectrum normalized to the bare substrate spectrum, T/T0, for a 20 × 20 μm2 h-BN ribbon array. Ribbon width w=158 nm, ribbon period D=400 nm and ribbon height h=40 nm. (c) Sketch of the nano-FTIR spectroscopy experiment. The near-field probing tip is scanned across (y-direction) the h-BN ribbon in 20-nm steps, as indicated by the dashed blue line. Near-field spectra are recorded as a function of the tip position (the detector signal is demodulated at the third harmonic of the tip tapping frequency, yielding s3(y, ω), as explained in the Materials and methods section). (d) Lower panel: Spectral line scan s3(y, ω), where each horizontal line corresponds to a spectrum recorded at a fixed y-position (vertical axis). Upper panel: Illustration of the real part of the z-component of the electric field (Re[Ez]) profile across the ribbon at the resonance frequency observed in the nano-FTIR spectra (lower panel). The AFM tip used was a NanoWorld Arrow-NCPT
Figure 2 from “Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit”: Far- and near-field spectroscopic characterization of h-BN ribbon arrays. (a) Sketch of the transmission spectroscopy experiment. Incoming light at normal incidence is polarized perpendicular to the ribbons to excite the HPhP resonance. (b) Transmission spectrum normalized to the bare substrate spectrum, T/T0, for a 20 × 20 μm2 h-BN ribbon array. Ribbon width w=158 nm, ribbon period D=400 nm and ribbon height h=40 nm. (c) Sketch of the nano-FTIR spectroscopy experiment. The near-field probing tip is scanned across (y-direction) the h-BN ribbon in 20-nm steps, as indicated by the dashed blue line. Near-field spectra are recorded as a function of the tip position (the detector signal is demodulated at the third harmonic of the tip tapping frequency, yielding s3(y, ω), as explained in the Materials and methods section). (d) Lower panel: Spectral line scan s3(y, ω), where each horizontal line corresponds to a spectrum recorded at a fixed y-position (vertical axis). Upper panel: Illustration of the real part of the z-component of the electric field (Re[Ez]) profile across the ribbon at the resonance frequency observed in the nano-FTIR spectra (lower panel).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Marta Autore, Peining Li, Irene Dolado, Francisco J Alfaro-Mozaz, Ruben Esteban, Ainhoa Atxabal, Fèlix Casanova, Luis E Hueso, Pablo Alonso-González, Javier Aizpurua, Alexey Y Nikitin, Saül Vélez & Rainer Hillenbrand
Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit
Light: Science & Applications 7, 17172 (2018)
DOI: https://doi.org/10.1038/lsa.2017.172

For the full article please follow this external link: https://rdcu.be/7B0F

The article: Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit by Marta Autore et. al, is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/