Fabrication and Photovoltaic Properties of Dye Sensitized Solar Cells on the Alternative Flexible Substrates

• Main Authors: Asheesh Nautiyal, 阿西
• Other Authors: Shou-Jen lee
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/86399913854719461121

博士 === 元智大學 === 機械工程學系 === 102 === Dye sensitized solar cells (DSSC) are an emerging photovoltaic technology with the potential for large scale manufacturing and low cost processing. However, the power conversion efficiency of DSSC must increase up to 10% to be commercially competitive with conventional solar cell technologies. DSSC do not completely absorb all of the photons from the visible and the near infrared range of the solar spectrum and consequently have lower short circuit photocurrent densities compared to inorganic photovoltaic devices. A variety of sensitizing dyes have been explored, but it is challenging to develop a single sensitizing dye that can absorb strongly in the visible and near-infrared spectrum. The focus of this doctoral thesis is on developing new flexible metallic and non metallic alternative materials for front and back electrodes which maintain energy transfer processes in order to improve light harvesting as well as lower the cost. The relatively low photovoltaic performance in DSSC on plastic substrates is mainly attributed to the low temperature processing limited by the thermal stability of the plastic substrate. Various low temperature processing methods have been developed for efficient front electrodes for plastic DSSC. With great efforts devoted and more novel methods developed, the PDMS polymer based DSSCs has been continuously improved from 2%-3%. Furthermore, many different novel structures have been designed for the flexible photoanodes. Promising results published by research have shown that the stainless steel SS 304 and SS 430 as counter electrodes have competitive performance while the transparent PDMS treated ones as front electrode. ITO thin films deposited on Polydimethylsiloxane PDMS substrates by RF sputtering at room temperature with different deposition time of 3, 5, 7, and 10 min with 60, 80, 100, and 120 nm, respectively. The results indicate the high transmittance of 83% and lowest resistivity of 3.8 x 10-5 Ωcm. The effect of surface roughness as regard to the reflectivity of stainless steel (SS 430 &; SS 304) substrate on DSSC structure was investigated. ECMP process was used to obtain the high reflective surface for stainless steel (SS 430 &; SS 304) substrate in order to prepare the solar cells. The I-V parameters showed that there was a significant difference in final efficiency among stainless steel (SS 430 &; SS 304) substrate, with polished 3.60 % and without polished 1.50 %.