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Microscopic observation of dye molecules for solar cells on a titania surface.

Koshiya S, Yamashita S, Kimoto K - Sci Rep (2016)

Bottom Line: A single dye molecule on the titania nanosheet was visualized for the first time.The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules.The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.

View Article: PubMed Central - PubMed

Affiliation: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

ABSTRACT
The lateral distribution and coverage of Ru-based dye molecules, which are used for dye-sensitized solar cells (DSCs), were directly examined on a titania surface using high-resolution scanning transmission electron microscopy (STEM). The clean surface of a free-standing titania nanosheet was first confirmed with atomic resolution, and then, the nanosheet was used as a substrate. A single dye molecule on the titania nanosheet was visualized for the first time. The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules. The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.

No MeSH data available.


Related in: MedlinePlus

ADF image simulation of dye molecule.(a,b) Structural model25 (a) and simulated ADF image (b) of a dye molecule. The QADF scale in (b) was set in the range of 0–0.6%. The parallelogram SDye in (b) corresponds to the area of a dye molecule on the surface.
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f2: ADF image simulation of dye molecule.(a,b) Structural model25 (a) and simulated ADF image (b) of a dye molecule. The QADF scale in (b) was set in the range of 0–0.6%. The parallelogram SDye in (b) corresponds to the area of a dye molecule on the surface.

Mentions: To evaluate the detectability of the dye molecules, STEM image simulation of a single dye molecule (N3 dye, C26H16N6O8RuS2) was performed. A structure model of a dye molecule2527, which is one of the possible binding configurations8 on a titania surface, and a simulated ADF image are presented in Fig. 2a,b, respectively. The area of the parallelogram SDye in Fig. 2b corresponds to the area of the dye molecule on a surface and equals 1.45 nm2; this value is necessary to estimate the coverage of dye molecules. The simulated image (Fig. 2b) shows the Ru atom position as a bright peak, whose quantitative contrast is 0.6% at the maximum. If dye molecules are attached on a titania nanosheet, the quantitative contrast proportionally increases with the coverage of the molecules because the incident probe is not greatly modified by the ultrathin specimen. Because the averaged quantitative contrast of the titania nanosheet was observed to be approximately 0.25% (Fig. 1), the intense Ru peak of the attached dye molecules can be recognized. Therefore, a single dye molecule is detectable in the ADF images when these molecules attached on titania nanosheets.


Microscopic observation of dye molecules for solar cells on a titania surface.

Koshiya S, Yamashita S, Kimoto K - Sci Rep (2016)

ADF image simulation of dye molecule.(a,b) Structural model25 (a) and simulated ADF image (b) of a dye molecule. The QADF scale in (b) was set in the range of 0–0.6%. The parallelogram SDye in (b) corresponds to the area of a dye molecule on the surface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834531&req=5

f2: ADF image simulation of dye molecule.(a,b) Structural model25 (a) and simulated ADF image (b) of a dye molecule. The QADF scale in (b) was set in the range of 0–0.6%. The parallelogram SDye in (b) corresponds to the area of a dye molecule on the surface.
Mentions: To evaluate the detectability of the dye molecules, STEM image simulation of a single dye molecule (N3 dye, C26H16N6O8RuS2) was performed. A structure model of a dye molecule2527, which is one of the possible binding configurations8 on a titania surface, and a simulated ADF image are presented in Fig. 2a,b, respectively. The area of the parallelogram SDye in Fig. 2b corresponds to the area of the dye molecule on a surface and equals 1.45 nm2; this value is necessary to estimate the coverage of dye molecules. The simulated image (Fig. 2b) shows the Ru atom position as a bright peak, whose quantitative contrast is 0.6% at the maximum. If dye molecules are attached on a titania nanosheet, the quantitative contrast proportionally increases with the coverage of the molecules because the incident probe is not greatly modified by the ultrathin specimen. Because the averaged quantitative contrast of the titania nanosheet was observed to be approximately 0.25% (Fig. 1), the intense Ru peak of the attached dye molecules can be recognized. Therefore, a single dye molecule is detectable in the ADF images when these molecules attached on titania nanosheets.

Bottom Line: A single dye molecule on the titania nanosheet was visualized for the first time.The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules.The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.

View Article: PubMed Central - PubMed

Affiliation: Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

ABSTRACT
The lateral distribution and coverage of Ru-based dye molecules, which are used for dye-sensitized solar cells (DSCs), were directly examined on a titania surface using high-resolution scanning transmission electron microscopy (STEM). The clean surface of a free-standing titania nanosheet was first confirmed with atomic resolution, and then, the nanosheet was used as a substrate. A single dye molecule on the titania nanosheet was visualized for the first time. The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules. The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.

No MeSH data available.


Related in: MedlinePlus