DefinePK

Abstract

The third generation of photovoltaic technology uses organic and inorganic dyes, to generate photo excited electrons, from which energy can be harvested. In dye sensitized solar cells (DSSCs), the dyes, which act as a sensitizer, harvest the sunlight and convert the solar energy to electrical energy. The usage of organic dyes was proposed as an alternative since it is a cheaper substitute, simple preparation methods and able to produce acceptable efficiency. This paper is aimed to investigate the absorption spectrum of extracted natural dyes of DSSCs by using different types of solvent; ethanol and deionized (DI) water. From the experiment, the relationship between the type of solvent used and the efficiency of the DSSCs to absorb more sunlight is investigated. Beside, the relationship between the extraction temperatures with its corresponding absorption spectrum is crucial to examine the optimum temperature for the dye. In this study, DSSCs were assembled by using extracted natural dyes from five different plants, which are Oxalis Triangularis, Roselle, Bawang Sabrang, Ardisia, and Mango using a very simple extraction technique. The extracted dyes were characterized using a spectrophotometer in the range between 400nm to 700nm. To find the optimum temperature of extracted dye, the dye is heated at different temperatures, which is room temperature, 50°C, 75°C and 100°C. In DI water solvent, the absorption peak of Bawang Sabrang is about 400nm while for Roselle is about 500nm. As for Ardisia and Oxalis Triangularis, it found that the peak absorption is at 550nm. Plus, the absorption peak of Mango is about 450nm. The absorption peak of Bawang Sabrang in ethanol is about 400nm while for Roselle is about 530nm. For Ardisia, the absorption peak is about 540nm. Plus, the absorption peak of Mango and Oxalis Triangularis is about 450nm and 420nm respectively. Besides, the temperatures also affect the efficiency and stability of DSSCs. From the experiment that has been conducted, most of the extracted dye in DI water solvent at temperature 50°C, shows the highest peak of absorption spectrum. While in ethanol solvent, the highest peak of absorption spectrum is at 100 °C.