Limits...
Orientation-Controllable ZnO Nanorod Array Using Imprinting Method for Maximum Light Utilization in Dye-Sensitized Solar Cells.

Jeong H, Song H, Lee R, Pak Y, Kumaresan Y, Lee H, Jung GY - Nanoscale Res Lett (2015)

Bottom Line: The orientation of the transferred ZNL such as laid, tilted, and standing ZnO NRs was dependent on the pitch and height of the ZnO NRs of the mold.The photoanode composed of the holey TiO2 film with the ZNL synergistically utilized the sunlight due to enhanced light scattering and absorption.The best power conversion efficiency of 8.5 % was achieved from the DSC with the standing ZNL, which represented a 33 % improvement compared to the reference cell with a planar TiO2.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea, heesoo@gist.ac.kr.

ABSTRACT
We present a holey titanium dioxide (TiO2) film combined with a periodically aligned ZnO nanorod layer (ZNL) for maximum light utilization in dye-sensitized solar cells (DSCs). Both the holey TiO2 film and the ZNL were simultaneously fabricated by imprint technique with a mold having vertically aligned ZnO nanorod (NR) array, which was transferred to the TiO2 film after imprinting. The orientation of the transferred ZNL such as laid, tilted, and standing ZnO NRs was dependent on the pitch and height of the ZnO NRs of the mold. The photoanode composed of the holey TiO2 film with the ZNL synergistically utilized the sunlight due to enhanced light scattering and absorption. The best power conversion efficiency of 8.5 % was achieved from the DSC with the standing ZNL, which represented a 33 % improvement compared to the reference cell with a planar TiO2.

No MeSH data available.


a Schematic of photoanode fabrication: simultaneous process of patterning a TiO2 film and transferring the ZnO NRs while imprinting. SEM images: b the mold with periodically aligned vertical ZnO NRs on the GaN substrate. The inset is a photo image of the whole ZnO NR mold (a quarter size of 2-in. GaN wafer). c The transferred tilted ZnO NR array on the TiO2 film. The inset shows a dye-adsorbed ZNL/TiO2 photoanode in an area of 4 cm2. d A defect area, where ZnO NRs were not transferred on the TiO2 film, showing hole trenches. e The holey TiO2 film, which was achieved by complete wet etching of the embedded ZnO NRs with an acidic solution. All scale bars, 2 μm
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4472652&req=5

Fig1: a Schematic of photoanode fabrication: simultaneous process of patterning a TiO2 film and transferring the ZnO NRs while imprinting. SEM images: b the mold with periodically aligned vertical ZnO NRs on the GaN substrate. The inset is a photo image of the whole ZnO NR mold (a quarter size of 2-in. GaN wafer). c The transferred tilted ZnO NR array on the TiO2 film. The inset shows a dye-adsorbed ZNL/TiO2 photoanode in an area of 4 cm2. d A defect area, where ZnO NRs were not transferred on the TiO2 film, showing hole trenches. e The holey TiO2 film, which was achieved by complete wet etching of the embedded ZnO NRs with an acidic solution. All scale bars, 2 μm

Mentions: Figure 1a is the schematic image of the fabrication process for the patterned TiO2 film with the ZNL on top. The grown ZnO NR has dual diameters of 250 nm (root part) and 500 nm (trunk part) as shown in the SEM image of Fig. 1b. The hole in the polymer template determined the root diameter of the NR, and the diameter of the ZnO NR above the hole was horizontally expanded with the growth. The ZnO NR array with a height of 2 μm at 800-nm pitch occupied an area of 4 cm2 (inset of Fig. 1b). The TiO2 film was prepared with TiO2 nanoparticulate paste by doctor blading method on a FTO glass, and the sample was baked at 80 °C for 30 min to obtain a semi-dried film instead of a fully dried film. The semi-dried TiO2 film was soft enough for being imprinted while still having an adhesive property strong enough to hold the transferred ZnO NRs during imprinting. In addition, the ZnO NR mold was treated with an AZ 100 solution prior to imprinting, which weakened the connection of the ZnO NRs to the GaN substrate, thereby inducing the easy separation of the ZnO NRs from the substrate during demolding (Additional file 1: Figure S2).Fig. 1


Orientation-Controllable ZnO Nanorod Array Using Imprinting Method for Maximum Light Utilization in Dye-Sensitized Solar Cells.

Jeong H, Song H, Lee R, Pak Y, Kumaresan Y, Lee H, Jung GY - Nanoscale Res Lett (2015)

a Schematic of photoanode fabrication: simultaneous process of patterning a TiO2 film and transferring the ZnO NRs while imprinting. SEM images: b the mold with periodically aligned vertical ZnO NRs on the GaN substrate. The inset is a photo image of the whole ZnO NR mold (a quarter size of 2-in. GaN wafer). c The transferred tilted ZnO NR array on the TiO2 film. The inset shows a dye-adsorbed ZNL/TiO2 photoanode in an area of 4 cm2. d A defect area, where ZnO NRs were not transferred on the TiO2 film, showing hole trenches. e The holey TiO2 film, which was achieved by complete wet etching of the embedded ZnO NRs with an acidic solution. All scale bars, 2 μm
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4472652&req=5

Fig1: a Schematic of photoanode fabrication: simultaneous process of patterning a TiO2 film and transferring the ZnO NRs while imprinting. SEM images: b the mold with periodically aligned vertical ZnO NRs on the GaN substrate. The inset is a photo image of the whole ZnO NR mold (a quarter size of 2-in. GaN wafer). c The transferred tilted ZnO NR array on the TiO2 film. The inset shows a dye-adsorbed ZNL/TiO2 photoanode in an area of 4 cm2. d A defect area, where ZnO NRs were not transferred on the TiO2 film, showing hole trenches. e The holey TiO2 film, which was achieved by complete wet etching of the embedded ZnO NRs with an acidic solution. All scale bars, 2 μm
Mentions: Figure 1a is the schematic image of the fabrication process for the patterned TiO2 film with the ZNL on top. The grown ZnO NR has dual diameters of 250 nm (root part) and 500 nm (trunk part) as shown in the SEM image of Fig. 1b. The hole in the polymer template determined the root diameter of the NR, and the diameter of the ZnO NR above the hole was horizontally expanded with the growth. The ZnO NR array with a height of 2 μm at 800-nm pitch occupied an area of 4 cm2 (inset of Fig. 1b). The TiO2 film was prepared with TiO2 nanoparticulate paste by doctor blading method on a FTO glass, and the sample was baked at 80 °C for 30 min to obtain a semi-dried film instead of a fully dried film. The semi-dried TiO2 film was soft enough for being imprinted while still having an adhesive property strong enough to hold the transferred ZnO NRs during imprinting. In addition, the ZnO NR mold was treated with an AZ 100 solution prior to imprinting, which weakened the connection of the ZnO NRs to the GaN substrate, thereby inducing the easy separation of the ZnO NRs from the substrate during demolding (Additional file 1: Figure S2).Fig. 1

Bottom Line: The orientation of the transferred ZNL such as laid, tilted, and standing ZnO NRs was dependent on the pitch and height of the ZnO NRs of the mold.The photoanode composed of the holey TiO2 film with the ZNL synergistically utilized the sunlight due to enhanced light scattering and absorption.The best power conversion efficiency of 8.5 % was achieved from the DSC with the standing ZNL, which represented a 33 % improvement compared to the reference cell with a planar TiO2.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Republic of Korea, heesoo@gist.ac.kr.

ABSTRACT
We present a holey titanium dioxide (TiO2) film combined with a periodically aligned ZnO nanorod layer (ZNL) for maximum light utilization in dye-sensitized solar cells (DSCs). Both the holey TiO2 film and the ZNL were simultaneously fabricated by imprint technique with a mold having vertically aligned ZnO nanorod (NR) array, which was transferred to the TiO2 film after imprinting. The orientation of the transferred ZNL such as laid, tilted, and standing ZnO NRs was dependent on the pitch and height of the ZnO NRs of the mold. The photoanode composed of the holey TiO2 film with the ZNL synergistically utilized the sunlight due to enhanced light scattering and absorption. The best power conversion efficiency of 8.5 % was achieved from the DSC with the standing ZNL, which represented a 33 % improvement compared to the reference cell with a planar TiO2.

No MeSH data available.