Improving the efficiency of dye-sensitized solar cells based on rare-earth metal modified bismuth ferrites

This study reports light energy harvesting characteristics of bismuth ferrite (BiFeO₃) and BiFO₃ doped with rare-earth metals such as neodymium (Nd), praseodymium (Pr), and gadolinium (Gd) dye solutions that were prepared by using the co-precipitation method. The structural, morphological, and optical properties of synthesized materials were studied, confirming that 5-50 nm sized synthesized particles have a well-developed and non-uniform grain size due to their amorphous nature. Moreover, the peaks of photoelectron emission for bare and doped BiFeO₃ were observed in the visible region at around 490 nm, while the emission intensity of bare BiFeO₃ was noticed to be lower than that of doped materials. Photoanodes were prepared with the paste of the synthesized sample and then assembled to make a solar cell. The natural and synthetic dye solutions of Mentha, Actinidia deliciosa, and green malachite, respectively, were prepared in which the photoanodes were immersed to analyze the photoconversion efficiency of the assembled dye-synthesized solar cells. The power conversion efficiency of fabricated DSSCs, which was confirmed from the I-V curve, is in the range from 0.84 to 2.15%. This study confirms that mint (Mentha) dye and Nd-doped BiFeO₃ materials were found to be the most efficient sensitizer and photoanode materials among all the sensitizers and photoanodes tested.