The effect of electrode immersion time and ageing on N719 dye-sensitized solar cells performance

Abstract

One of the most promising devices belonging to the third generation of photovoltaic technologies is dye-sensitized solar cell (DSSC). It can be considered as an economic substitute for the first and second generation of solar cells which provides relatively high conversion efficiency at low cost of material and simple manufacturing. This technology is widely developed nowadays thus it can contribute the meeting of the current and future energy demands. However, much work should be done to increase solar-electricity conversion efficiency of DSSC. It is identified that a crucial component which strongly affects the performance of the working dye-sensitized cell is dye sensitizer used to enhance the light harvesting. The adjustment of the amount of the adsorbed dye by a modification of photoelectrode immersion time in dye solution plays a crucial role. The objective of this study was to report the influence of electrode immersion time on dye-sensitized solar cells performance and to evaluate the stability of obtained cells. DSSC assemblies were prepared in the sandwich way with the working area equal to 0.8 cm2. The impact of various immersion times in N719 dye solution of the TiO2 covered photoelectrodes have been investigated. In the study, the process of encapsulation of the cells with sealant gaskets was enhanced which caused the improvement of the stability and tightness of the obtained DSSC devices. The methodological process adopted in this investigation includes measurements of current-voltage (I-V) characteristics performed right after cell preparation, and after 72 hours to evaluate the role of ageing. The characterization of the obtained solar cells was carried out under standard test conditions (STC; temperature 25°C, irradiance 100 mW/cm2, air mass AM 1.5). On the basis of I-V curves measurements, characteristic operating parameters of the obtained DSSC assemblies such as open circuit voltage (VOC), short circuit current (ISC), and maximum power point (MPP) have been established. The results of this research indicate that the time of electrode immersion in the dye solution affects strongly the DSSC performance. Thus, the control of the stage of the dye adsorption by the TiO2 layer is vitally important.