Photovoltaic Performance of the Dye-sensitized Solar Cells based on the TiO2 film photoelectrodes fabricated by a sol-gel method

• Main Authors: Wei-YunChang, 張瑋芸
• Other Authors: Shyan-Lung Chung
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/93631158404981737871

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 100 === The sol-spin method is an easy and low-cost process to prepare the TiO2 films, however, there is a layer thickness limitation and it’s difficult to prepare films without cracking after calcination in the present researches appling to dye-sensitized solar cells. Nano-structured TiO2 films with different morphologies were fabricated and used as photo electrodes for assembling of dye-sensitized solar cells (DSSC) and the DSSCs were tested for their photovoltaic performance. Titanium n-butoxide (Ti(OC4H9)4, 99%, Acros) was hydrolyzed in the presence of isopropyl alcohol and catalyzed by nitric acid. After peptization and addition of polymeric additives, the resultant sol was spin-coated on transparent fluorine-doped tin oxide substrates to obtain nano-structured TiO2 films. By controlling the added amounts of polymeric additives, the morphology of the nano-structured TiO2 film was found to vary significantly from isolated- island form with numerous cracks to continuous film composed of nano-sized particles, and a remarkable increase of film thickness with 7-8 μm by sol-spin method is also achieved. The photovoltaic performance of DSSC depends strongly on the morphology of the film, once the continuous film is realized, the short circuit current was enhanced significantly by controlling the particle size and specific area which is the result of nitric acid concentration adjustment (pH difference). Under an optimum condition, a photoelectrical conversion efficiency (η) of 6.63 was obtained (with Voc＝0.68V, F.F.＝0.52 and Isc＝18.76 mA/cm2). In this thesis, the experimental procedure and the effects of nitric acid and the polymeric additives on the film morphology are described. The effects of the film morphology on the photovoltaic performance are also discussed.