Variations in Power Conversion Efficiency on n-Type Dye-Sensitized Solar Cells with Synthesized TiO2 Nanoparticle: A Thickness Effect of Active Layer

Recently, many researchers have made progress in studies aimed at enhancing the power conversion efficiency (PCE) of n-type dye-sensitized solar cells (DSSCs). This paper presents a systematic investigation focused on improving the PCEs of n-type DSSCs by synthesizing TiO2 nanoparticle active layers and varying their thickness. The study found that increasing the TiO2 layer thickness up to 17 µm resulted in a steady 41% increase in PCE, primarily owing to the enhanced photocurrent density in the n-type DSSCs. This improvement is attributed to the enhanced light harvesting effect. As a result, n-type DSSC with 17 µm thick TiO2 layer demonstrates a relatively high Jsc value of 8.42 mA/cm2, achieving an overall PCE of 4.02%. In contrast, the n-type DSSC with a 6 µm thick TiO2 layer exhibits a much lower Jsc value of 5.55 mA/cm2, leading to a reduced PCE. This result represents at least a 52% increase in current density, indicating that the optimal thickness of the TiO2 active layer is a critical factor influencing the PCE of DSSCs.