Surface modification of photoanodes by HCl treatment to improve the efficiency of DSSC

Abstract

Dye-sensitized solar cells are having an essential role in future photovoltaic devices. To improve the efficiency of DSSC is become very relevant and we are trying it by doing a simple solution method HCl treatment on photoanodes before dye anchoring. So we have used two different dyes for this purpose in this project. Ruthenium based N719 dye, which has been reported for high photon to current conversion efficiency in DSSC. And a squarine based organic SQ1 dye, as it is more environmental friendly and having great importance. And by using the solution method treatment of HCl, we were successfully increased the efficiency of N719 dye and SQ1 dye. This is mainly because of the surface protonation taking place at the photoanodes by the HCl treatment, and we have confirmed it by different characterization techniques. As both the dyes are having a carboxylic anchoring group, surface protonation having an essential role in dye anchoring. Dye desorption studies carried out to understand how dye anchoring effect is effected by HCl treatment. With the help of electrochemical impedance spectroscopy, we were able to detect the increment in the recombination resistance, chemical capacitance and lifetime of the electrons of the HCl treated devices. The method we have used is easier, efficient and low cost to improve DSSC efficiency.