Improved the DSSCs performance by sensitizing eight natural dyes and varying the annealing process on the TiO2

Abstract

The use of natural photosensitizers applied to dye-sensitized solar cells (DSSCs) is the key to getting inexpensive and abundant materials for solar cells. However, the low recorded efficiency remains a crucial concern. Here, we investigated and extracted eight natural dyes as photosensitizers for DSSCs intensively. We also studied the impact of annealing on the photoanode’s titanium dioxide (TiO2). First, from the characterization measurements, we found the compound of all the dyes can be utilized in DSSCs, and the performance measurement shows that all natural dyes exhibited great performances as photosensitizers in DSSCs, in which their JSC and VOC values are approximately 0.52–2.88 mA cm−2 and 0.63 to 0.76 V, respectively. The best-recorded conversion efficiency is 4.71%, which was extracted from red gambier fruits. Second, increasing the annealing temperature on the photoanode in our device caused a decrease in the efficiency of the DSSCs. This is caused by the phase of TiO2 changing from anatase to brookite when the temperature increases.