Enhancement of the light harvesting efficiency in a dye-sensitized solar cell by a patterned reflector

Light harvesting efficiency plays an important role in improving the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). Many researchers have employed a scatter layer to improve the light harvesting efficiency of DSSCs. In this paper, we propose a different DSSC structure that employs a patterned reflection layer to enhance the light harvesting efficiency and improve the PCE by reusing reflected light. Optical simulation data were collected through an optical analysis according to various patterns of the reflection layer. The optical simulation results revealed that the light harvesting efficiency of a rectangular patterned reflection layer was higher than that of other patterns. We evaluated the cell efficiency with current density-voltage characteristic curves by a solar simulator. The DSSC structures with a rectangular patterned reflection layer exhibited higher current densities and higher PCE values (22% enhancement) than those of traditional DSSCs, because light that passed through the photoanode was reflected, thereby making it possible to reuse it.