Property of prepared N719 dye using gamma-irradiation and its dye-sensitized solar cell application

Solar photovoltaic cells, dye-sensitized solar cells (DSSCs), capable of directly converting sunlight into electrical power, are one of the most promising devices in the search for sustainable and renewable sources of clean energy. In particular, dyes used as a sensitizer in DSSCs are very important to increase the efficiency including a light harvesting portion (broad spectrum, increased absorbance), acidic ligands (ex; carboxylic or phosphonic acid) to attach to the semiconductor surface, and ligands to increase the solubility in the solution and reduce aggregation between dyes in DSSCs. Also, dyes have to possess thermal and chemical stability. In the present study, we tried to develop an advanced dye, using the interaction between the dye and gamma irradiation. We also describe the preparation of structurally changed dyes using gamma-irradiation and the results achieved. Specifically, a commercialized dye, N719 was investigated. N719 dye solutions having different properties against non-treatment dyes were prepared from gamma irradiation. The dyes constantly showed the same color (red pink) characteristics as 1Gy to the 1kGy of irradiation dose. Based on the optical property of the dyes, interesting structural characteristics were shown as a gradually increased absorption peak in accordance with the irradiation dose. The results might indicate that the dye structure was partially changed by an interaction between the gamma-irradiation. The DSSC efficiency of the dyes in terms of photovoltaic performance was clearly suggested from the reaction between the dyes and gamma-irradiation. In particular, the results suggest that the existence of an appropriate amount of OHgroup in the dye molecules might control the effect on DSSC efficiency. Therefore, it can be applicable to the needs for an appropriate sensitizer with certain added functions in DSSC using a radiolysis technique. In addition, it can be used effectively in various industrial fields and is applicable to diverse systems