Investigating the effect of different quantum dots on the absorption spectrum and characteristics of quantum dot sensitized solar cells

Abstract: Quantum dot sensitized solar cells are among the new generations of solar cells that have attracted much attention. Theoretical and simulation studies have predicted high efficiency for these cells so that in the future, these cells could be an excellent alternative to silicon solar cells. Other advantages of these cells are their ease of fabrication and cheaper manufacturing methods than existing cells. This paper's main idea is to simulate the effect of different quantum dots on the optical and electrical characteristics of these cells and, in particular, the efficiency. We then simulated the effect of simultaneous sensitizing by different quantum dots, and we observed that the cell's light absorption and the efficiency in simultaneous sensitizing, increased. Then we experimentally studied one of the cells that give the best simulation result (PbS/CdS co-sensitized). We deposited the quantum dots on transparent TiO2, and we obtained the light absorption, efficiency, and other characteristics of cells. Further, we investigated the effect of cobalt sulfide as the counter electrode in PbS/CdS, instead of platinum and gold, and we found that the efficiency has increased.