Opening direction of TiO2 nanotube arrays for Dye-Sensitized Solar Cells

• Main Authors: Ching-Wen Hsu, 許淨雯
• Other Authors: Chaochin Su
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/v6zyr6

碩士 === 國立臺北科技大學 === 有機高分子研究所 === 100 === The aim of this thesis is to fabricate a TiO2 nanotube based dye-sensitized solar cells (DSSCs) with the front-side illumination. In this work, the formation of ordered anatase TiO2 nanotube (TNT) arrays was carried out by potentiostatic anodization process followed by annealing at 450 oC for particular time. Subsequently, tube-shaped and pipe-shaped free standing TNT arrays were fabricated by voltage-pulse method, in which voltage pulses were applied for a short time at the end of the anodization process. The TNT arrays were detached and transferred onto the FTO substrate using TiO2 NP paste as an interface and used as a photoanode in DSSCs for front-side illumination. The first part of this work is the preparation of tube-shaped TNT arrays by varying the second anodization voltage. The free-standing TNT arrays were attached on the FTO substrate in two directions, one as upright (face-up) and another one is inverted (bottom-up). In order to investigate the effect of TNT array direction in DSSCs performance, the characteristics analysis of N719-based DSSCs, such as current density-voltage (J-V) and incident photo-to-current conversion efficiency (IPCE) measurements were performed. The second part of this work is the preparation of pipe-shaped TNT arrays by elevating the anodizing voltage at the end of second anodization process. Elevating the voltage helps to break the adhesion of the TNT arrays from the underlying Ti substrate and simultaneously open their closed bottom. Adsorption of N719 dye for the closed bottom and opened bottom TNT array photoanodes were studied. The photoelectrical performance of DSSCs with closed bottoms and opened bottoms TNT arrays were investigated and compared with each other. Hereby, from the above two works we can conclude that the front-side illuminated TNT arrays based DSSCs demonstrated a better improvement in the photoconversion efficiency. The free-standing TNT arrays were attached on the FTO substrate in three directions, one as upright (face-up), another is inverted (bottom-up), and the other is open-end. In order to investigate the effect of TNT array direction in DSSCs performance, inverted (bottom-up) has the best efficiency is 6.93 %. And incident photo-to-current conversion efficiency (IPCE) measurements were 47.63 % at 530 nm wavelength in open-end.