37 research outputs found
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Noninvasive Cathodoluminescence-Activated Nanoimaging of Dynamic Processes in Liquids.
In situ electron microscopy provides remarkably high spatial resolution, yet electron beam irradiation often damages soft materials and perturbs dynamic processes, requiring samples to be very robust. Here, we instead noninvasively image the dynamics of metal and polymer nanoparticles in a liquid environment with subdiffraction resolution using cathodoluminescence-activated imaging by resonant energy transfer (CLAIRE). In CLAIRE, a free-standing scintillator film serves as a nanoscale optical excitation source when excited by a low energy, focused electron beam. We capture the nanoscale dynamics of these particles translating along and desorbing from the scintillator surface and demonstrate 50 ms frame acquisition and a range of imaging of at least 20 nm from the scintillator surface. Furthermore, in contrast with in situ electron microscopy, CLAIRE provides spectral selectivity instead of relying on scattering alone. We also demonstrate through quantitative modeling that the CLAIRE signal from metal nanoparticles is impacted by multiplasmonic mode interferences. Our findings demonstrate that CLAIRE is a promising, noninvasive approach for super-resolution imaging for soft and fluid materials with high spatial and temporal resolution
Recommended from our members
Noninvasive Cathodoluminescence-Activated Nanoimaging of Dynamic Processes in Liquids
<i>In situ</i> electron microscopy provides remarkably
high spatial resolution, yet electron beam irradiation often damages
soft materials and perturbs dynamic processes, requiring samples to
be very robust. Here, we instead noninvasively image the dynamics
of metal and polymer nanoparticles in a liquid environment with subdiffraction
resolution using cathodoluminescence-activated imaging by resonant
energy transfer (CLAIRE). In CLAIRE, a free-standing scintillator
film serves as a nanoscale optical excitation source when excited
by a low energy, focused electron beam. We capture the nanoscale dynamics
of these particles translating along and desorbing from the scintillator
surface and demonstrate 50 ms frame acquisition and a range of imaging
of at least 20 nm from the scintillator surface. Furthermore, in contrast
with <i>in situ</i> electron microscopy, CLAIRE provides
spectral selectivity instead of relying on scattering alone. We also
demonstrate through quantitative modeling that the CLAIRE signal from
metal nanoparticles is impacted by multiplasmonic mode interferences.
Our findings demonstrate that CLAIRE is a promising, noninvasive approach
for super-resolution imaging for soft and fluid materials with high
spatial and temporal resolution
Recommended from our members
Noninvasive Cathodoluminescence-Activated Nanoimaging of Dynamic Processes in Liquids
<i>In situ</i> electron microscopy provides remarkably
high spatial resolution, yet electron beam irradiation often damages
soft materials and perturbs dynamic processes, requiring samples to
be very robust. Here, we instead noninvasively image the dynamics
of metal and polymer nanoparticles in a liquid environment with subdiffraction
resolution using cathodoluminescence-activated imaging by resonant
energy transfer (CLAIRE). In CLAIRE, a free-standing scintillator
film serves as a nanoscale optical excitation source when excited
by a low energy, focused electron beam. We capture the nanoscale dynamics
of these particles translating along and desorbing from the scintillator
surface and demonstrate 50 ms frame acquisition and a range of imaging
of at least 20 nm from the scintillator surface. Furthermore, in contrast
with <i>in situ</i> electron microscopy, CLAIRE provides
spectral selectivity instead of relying on scattering alone. We also
demonstrate through quantitative modeling that the CLAIRE signal from
metal nanoparticles is impacted by multiplasmonic mode interferences.
Our findings demonstrate that CLAIRE is a promising, noninvasive approach
for super-resolution imaging for soft and fluid materials with high
spatial and temporal resolution
Recommended from our members
Noninvasive Cathodoluminescence-Activated Nanoimaging of Dynamic Processes in Liquids
<i>In situ</i> electron microscopy provides remarkably
high spatial resolution, yet electron beam irradiation often damages
soft materials and perturbs dynamic processes, requiring samples to
be very robust. Here, we instead noninvasively image the dynamics
of metal and polymer nanoparticles in a liquid environment with subdiffraction
resolution using cathodoluminescence-activated imaging by resonant
energy transfer (CLAIRE). In CLAIRE, a free-standing scintillator
film serves as a nanoscale optical excitation source when excited
by a low energy, focused electron beam. We capture the nanoscale dynamics
of these particles translating along and desorbing from the scintillator
surface and demonstrate 50 ms frame acquisition and a range of imaging
of at least 20 nm from the scintillator surface. Furthermore, in contrast
with <i>in situ</i> electron microscopy, CLAIRE provides
spectral selectivity instead of relying on scattering alone. We also
demonstrate through quantitative modeling that the CLAIRE signal from
metal nanoparticles is impacted by multiplasmonic mode interferences.
Our findings demonstrate that CLAIRE is a promising, noninvasive approach
for super-resolution imaging for soft and fluid materials with high
spatial and temporal resolution
Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite
Photovoltaic devices based on hybrid perovskite materials have exceeded 22% efficiency due to high charge-carrier mobilities and lifetimes. Properties such as photocurrent generation and open-circuit voltage are influenced by the microscopic structure and orientation of the perovskite crystals, but are difficult to quantify on the intra-grain length scale and are often treated as homogeneous within the active layer. Here, we map the local short-circuit photocurrent, open-circuit photovoltage, and dark drift current in state-of-the-art methylammonium lead iodide solar cells using photoconductive atomic force microscopy. We find, within individual grains, spatially correlated heterogeneity in short-circuit current and open-circuit voltage up to 0.6 V. These variations are related to different crystal facets and have a direct impact on the macroscopic power conversion efficiency. We attribute this heterogeneity to a facet-dependent density of trap states. These results imply that controlling crystal grain and facet orientation will enable a systematic optimization of polycrystalline and single-crystal devices for photovoltaic and lighting applications