Fabrication of High-Efficiency (11%) Dye-Sensitized Solar Cells in Backside Illumination Mode by Anode Surface Treatments

• Main Authors: Choa-HsuanChang, 張櫂玹
• Other Authors: Chin-Cheng Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/djrjpn

碩士 === 國立成功大學 === 化學工程學系 === 102 === In order to improve the efficiency of the dye-sensitized solar cells (DSSCs) substantially in the backside illumination mode with the flexible substrate. The study elucidated several effective anode surface treatment methods, focusing on two key factors: light harvesting efficiency and carrier extraction efficiency. There are divided into four parts. The first part was to find out the optimum mesoporous TiO2 thickness, 11.4 μm, and the thickness was used in other various surface treated-substrates. TiCl4(aq) pre-treatment and post-treatment were employed to retard the charge recombination near the Ti substrate and to reduce the electrons transfer resistance in TiO2 film. An optimized efficiency of 5% was obtained. The second part employed two-steps wet etching process. Ti substrates were treated with HF solution and KOH solution sequentially to form micro- and nano-structures and were then used as the flexible substrate in DSSCs. An optimized efficiency of 5.9% was achieved. The third part developed a very powerful retarding current leakage method, i.e., O2 plasma pre-treatment, improving the efficiency from 5.9% to 7.8%. The fourth part employed a reactive ion etching (RIE) method to fabricate high aspect ratio and regular pattern of micro scale structures to further improve light harvesting and carrier extraction. The best efficiency was 11%, which is the highest efficiency for backside illumination mode DSSCs made of TiO2 nanoparticles reported in the literature. The technologies developed in the study can not only apply in DSSC but perovskite-sensitized solar cells. Besides, structure concept can be used for other kinds of solar cells.