Abstract
TiO2 nanotube arrays (NTA), of 17-37 μm in thickness, detached from anodic oxidized Ti foils were used as photoanodes for dye-sensitized solar cells (DSSCs). Photovoltaic measurements under frontside and backside illumination showed that frontside illumination geometry provided better cell performance than backside illumination did. A cell assembled with 30 μm thick NTA film produced the greatest photocurrent and light conversion efficiency. Despite an advantageous architecture for electron transport, electron trapping remained a limiting factor for both illumination geometries, due to the presence of crystal grains in the NTA walls. Intensity-modulated photocurrent spectroscopy (IMPS) analysis showed that electron transport in the front-illuminated cells comprises both trap-free and trap-limited diffusion modes, whereas electrons in the back-illuminated cells travel only by trap-limited diffusion. The trap-free diffusion mechanism determines front-illuminated cell performance. Electrochemical impedance spectroscopy analysis showed the front-illuminated NTA-based DSSCs have a charge collection efficiency of better than 90%, even at 30 μm NTA film thickness. Large crystal size results in low trap state density in the NTA film, and this effect may result in a more extensive trap-free diffusion zone in the films, which facilitates charge collection.
| Original language | English |
|---|---|
| Pages (from-to) | 15018-15024 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry C |
| Volume | 115 |
| Issue number | 30 |
| DOIs | |
| Publication status | Published - 2011 Aug 4 |
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All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Energy(all)
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Electron transport patterns in TiO2 nanotube arrays based dye-sensitized solar cells under frontside and backside illuminations. / Hsiao, Po Tsung; Liou, Yong Jin; Teng, Hsisheng.
In: Journal of Physical Chemistry C, Vol. 115, No. 30, 04.08.2011, p. 15018-15024.Research output: Contribution to journal › Article
TY - JOUR
T1 - Electron transport patterns in TiO2 nanotube arrays based dye-sensitized solar cells under frontside and backside illuminations
AU - Hsiao, Po Tsung
AU - Liou, Yong Jin
AU - Teng, Hsisheng
PY - 2011/8/4
Y1 - 2011/8/4
N2 - TiO2 nanotube arrays (NTA), of 17-37 μm in thickness, detached from anodic oxidized Ti foils were used as photoanodes for dye-sensitized solar cells (DSSCs). Photovoltaic measurements under frontside and backside illumination showed that frontside illumination geometry provided better cell performance than backside illumination did. A cell assembled with 30 μm thick NTA film produced the greatest photocurrent and light conversion efficiency. Despite an advantageous architecture for electron transport, electron trapping remained a limiting factor for both illumination geometries, due to the presence of crystal grains in the NTA walls. Intensity-modulated photocurrent spectroscopy (IMPS) analysis showed that electron transport in the front-illuminated cells comprises both trap-free and trap-limited diffusion modes, whereas electrons in the back-illuminated cells travel only by trap-limited diffusion. The trap-free diffusion mechanism determines front-illuminated cell performance. Electrochemical impedance spectroscopy analysis showed the front-illuminated NTA-based DSSCs have a charge collection efficiency of better than 90%, even at 30 μm NTA film thickness. Large crystal size results in low trap state density in the NTA film, and this effect may result in a more extensive trap-free diffusion zone in the films, which facilitates charge collection.
AB - TiO2 nanotube arrays (NTA), of 17-37 μm in thickness, detached from anodic oxidized Ti foils were used as photoanodes for dye-sensitized solar cells (DSSCs). Photovoltaic measurements under frontside and backside illumination showed that frontside illumination geometry provided better cell performance than backside illumination did. A cell assembled with 30 μm thick NTA film produced the greatest photocurrent and light conversion efficiency. Despite an advantageous architecture for electron transport, electron trapping remained a limiting factor for both illumination geometries, due to the presence of crystal grains in the NTA walls. Intensity-modulated photocurrent spectroscopy (IMPS) analysis showed that electron transport in the front-illuminated cells comprises both trap-free and trap-limited diffusion modes, whereas electrons in the back-illuminated cells travel only by trap-limited diffusion. The trap-free diffusion mechanism determines front-illuminated cell performance. Electrochemical impedance spectroscopy analysis showed the front-illuminated NTA-based DSSCs have a charge collection efficiency of better than 90%, even at 30 μm NTA film thickness. Large crystal size results in low trap state density in the NTA film, and this effect may result in a more extensive trap-free diffusion zone in the films, which facilitates charge collection.
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U2 - 10.1021/jp202681c
DO - 10.1021/jp202681c
M3 - Article
VL - 115
SP - 15018
EP - 15024
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 30
ER -