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Scattering Intensity and Directionality Probed Along Individual Zinc Oxide Nanorods with Precisely Controlled Light Polarization and Nanorod Orientation.

Choi DS, Singh M, Song S, Chang JY, Kang Y, Hahm JI - Photonics (2015)

Bottom Line: We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs.The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices.Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Georgetown University, 37th & O Sts. NW., Washington, DC 20057, USA.

ABSTRACT

We elucidated the light-matter interaction of individual ZnO NRs with a monochromatic beam of linearly polarized light that scatters elastically from the ZnO NRs by performing forward scattering and back-aperture imaging in a dark-field setting. We precisely controlled the electric field vector of the incident light and the NR orientation within the plane of light interaction during both modes of measurement, and spatially resolved the scattering response from different interaction points along the NR long axis. We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs. We identified distinctive scattering profiles from individual ZnO NRs subject to incident light polarization with controlled NR orientation from the forward dark-field scattering and back-aperture imaging modes. The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices. Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

No MeSH data available.


Related in: MedlinePlus

The NR-position dependent scattering signals under the two excitation conditions of E∥ and E⊥ were collected over the entire length of the ZnO NR∥ and plotted against the analyzer rotation. Red and blue symbols in all graphs are the experimental data when excitation polarizations of E∥ and E⊥ were used, respectively. Lines represent curve fits for the corresponding set of data. (A) The position-dependent scattering signal was averaged over the entire length of the NR∥ and plotted as a function of the analyzer angle. For the same exposure of 50 ms, the overall scattering intensity from the same NR was much lower when E⊥ was used as excitation instead of E∥. (B) The average scattering intensity was normalized with respect to the highest intensity values measured at each excitation condition and graphed as a function of the analyzer rotation. (C) Polarization anisotropy values calculated from the data shown in (B) follow a cos2θ dependence on the analyzer angle, θ. (D,E) Polar plots of average scattering intensities from the ZnO NR∥ under (D) E∥ and (E) E⊥ excitation are shown.
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Figure 3: The NR-position dependent scattering signals under the two excitation conditions of E∥ and E⊥ were collected over the entire length of the ZnO NR∥ and plotted against the analyzer rotation. Red and blue symbols in all graphs are the experimental data when excitation polarizations of E∥ and E⊥ were used, respectively. Lines represent curve fits for the corresponding set of data. (A) The position-dependent scattering signal was averaged over the entire length of the NR∥ and plotted as a function of the analyzer angle. For the same exposure of 50 ms, the overall scattering intensity from the same NR was much lower when E⊥ was used as excitation instead of E∥. (B) The average scattering intensity was normalized with respect to the highest intensity values measured at each excitation condition and graphed as a function of the analyzer rotation. (C) Polarization anisotropy values calculated from the data shown in (B) follow a cos2θ dependence on the analyzer angle, θ. (D,E) Polar plots of average scattering intensities from the ZnO NR∥ under (D) E∥ and (E) E⊥ excitation are shown.

Mentions: In Figure 3, the scattering signal over the entire length of the ZnO NR∥ is further processed and compared for the two excitation conditions of E∥ and E⊥ by plotting NR-position averaged scattering values against the analyzer rotation. Specifically, the scattering dependence of the ZnO NR∥ on the incoming E-field polarization is evaluated by plotting the average scattering intensity, normalized scattering intensity, and polarization anisotropy (PA) as a function of the analyzer rotation in Figure 3A, B, and C, respectively. In all graphs of Figure 3, data collected from the two cases of E∥ and E⊥ (and their respective curve fits) are represented as red and blue points (and lines), respectively. For the normalized intensity plots, the average scattering intensity is normalized with respect to the highest and lowest intensity values measured at each excitation condition. The PA values plotted in Figure 3C are obtained by the equation shown below, which defines PA as the ratio of the difference between the scattered light intensities for polarized light under E∥ and E⊥ to the sum of those values at a given analyzer angle.(1)PA=IE‖−IE⊥IE‖+IE⊥


Scattering Intensity and Directionality Probed Along Individual Zinc Oxide Nanorods with Precisely Controlled Light Polarization and Nanorod Orientation.

Choi DS, Singh M, Song S, Chang JY, Kang Y, Hahm JI - Photonics (2015)

The NR-position dependent scattering signals under the two excitation conditions of E∥ and E⊥ were collected over the entire length of the ZnO NR∥ and plotted against the analyzer rotation. Red and blue symbols in all graphs are the experimental data when excitation polarizations of E∥ and E⊥ were used, respectively. Lines represent curve fits for the corresponding set of data. (A) The position-dependent scattering signal was averaged over the entire length of the NR∥ and plotted as a function of the analyzer angle. For the same exposure of 50 ms, the overall scattering intensity from the same NR was much lower when E⊥ was used as excitation instead of E∥. (B) The average scattering intensity was normalized with respect to the highest intensity values measured at each excitation condition and graphed as a function of the analyzer rotation. (C) Polarization anisotropy values calculated from the data shown in (B) follow a cos2θ dependence on the analyzer angle, θ. (D,E) Polar plots of average scattering intensities from the ZnO NR∥ under (D) E∥ and (E) E⊥ excitation are shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643738&req=5

Figure 3: The NR-position dependent scattering signals under the two excitation conditions of E∥ and E⊥ were collected over the entire length of the ZnO NR∥ and plotted against the analyzer rotation. Red and blue symbols in all graphs are the experimental data when excitation polarizations of E∥ and E⊥ were used, respectively. Lines represent curve fits for the corresponding set of data. (A) The position-dependent scattering signal was averaged over the entire length of the NR∥ and plotted as a function of the analyzer angle. For the same exposure of 50 ms, the overall scattering intensity from the same NR was much lower when E⊥ was used as excitation instead of E∥. (B) The average scattering intensity was normalized with respect to the highest intensity values measured at each excitation condition and graphed as a function of the analyzer rotation. (C) Polarization anisotropy values calculated from the data shown in (B) follow a cos2θ dependence on the analyzer angle, θ. (D,E) Polar plots of average scattering intensities from the ZnO NR∥ under (D) E∥ and (E) E⊥ excitation are shown.
Mentions: In Figure 3, the scattering signal over the entire length of the ZnO NR∥ is further processed and compared for the two excitation conditions of E∥ and E⊥ by plotting NR-position averaged scattering values against the analyzer rotation. Specifically, the scattering dependence of the ZnO NR∥ on the incoming E-field polarization is evaluated by plotting the average scattering intensity, normalized scattering intensity, and polarization anisotropy (PA) as a function of the analyzer rotation in Figure 3A, B, and C, respectively. In all graphs of Figure 3, data collected from the two cases of E∥ and E⊥ (and their respective curve fits) are represented as red and blue points (and lines), respectively. For the normalized intensity plots, the average scattering intensity is normalized with respect to the highest and lowest intensity values measured at each excitation condition. The PA values plotted in Figure 3C are obtained by the equation shown below, which defines PA as the ratio of the difference between the scattered light intensities for polarized light under E∥ and E⊥ to the sum of those values at a given analyzer angle.(1)PA=IE‖−IE⊥IE‖+IE⊥

Bottom Line: We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs.The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices.Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Georgetown University, 37th & O Sts. NW., Washington, DC 20057, USA.

ABSTRACT

We elucidated the light-matter interaction of individual ZnO NRs with a monochromatic beam of linearly polarized light that scatters elastically from the ZnO NRs by performing forward scattering and back-aperture imaging in a dark-field setting. We precisely controlled the electric field vector of the incident light and the NR orientation within the plane of light interaction during both modes of measurement, and spatially resolved the scattering response from different interaction points along the NR long axis. We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs. We identified distinctive scattering profiles from individual ZnO NRs subject to incident light polarization with controlled NR orientation from the forward dark-field scattering and back-aperture imaging modes. The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices. Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

No MeSH data available.


Related in: MedlinePlus