The Study of Various Mixed Ratios of TiO2 to ZnO for Dye-sensitized Solar Cells

• Main Authors: MinShun, Hsu, 許閔順
• Other Authors: 蘇昭瑾
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/u7y4hq

碩士 === 國立臺北科技大學 === 有機高分子研究所 === 100 === In addition to the widely used TiO2 photoanodes in dye-sensitized solar cells (DSSCs), ZnO is gaining particular importance due to its higher electron mobility than that of anatase TiO2. ZnO possess a similar band gap (3.3 eV) compared to that of TiO2, and it can crystallize under low temperature. ZnO crystallizes in two different forms, in which wurtzite structure is the most stable phase. ZnO has unique properties such as high potential, easy preparation, higher binding energy and so on. Due to its high electron mobility, the recombination of electrons will be reduced and hence the lifetime of the DSSCs will be high in ZnO based photoanodes. However, the application of ZnO in DSSCs has obtained a lower efficiency when compared with TiO2 photoanode. This can be due to the longer immersion time of ZnO film in dye. While the ZnO films are immersed in dye for long duration, Zn on the surface of ZnO will start to dissolve and the formation of Zn2+/dye complex will occur. These Zn2+/dye complex can form an agglomerated thick layer, which hinders the electron injection. This can be avoiding by the immersion of ZnO film in dye for short duration. The formation of ZnO nanoparticle size, morphology, and the polymorphs has a profound effect on the dye-sensitized solar cells. In this thesis, five parts of work has been carried out such as the preparation of aggregated ZnO nanoparticles by sol-gel approach, the preparation of ZnO nanoparticles by hydrothermal approach, the preparation of ZnO@TiO2 core shell NPs by sol-gel approach, the preparation of ZnO/TiO2 composite NPs by blending and the preparation of ZnO/TiO2 using layer by layer approach. These nanomaterials have been used as photoanode in the application of dye-sensitized solar cells. Eventually, different coating methods were performed for the application of these materials in dye-sensitized solar cells. The above prepared samples have been characterized using transmission electron microscopy, scanning electron microscopy and X-ray diffraction analyzes. DSSCs fabricated using these photoanodes were evaluated using I-V measurements, IPCE and dye adsorption analyzes.