Investigating the Physical Properties of FeCu and its Potential use in Dye Sensitized Solar Cells

Abstract

The development of solar cells has revolutionized the renewable energy sector and still holds significant potential for further advancements. Different solar cell technologies have been proposed and utilized in practical applications. This work is focused on the special class of dye-sensitized solar cells which have been developed with the aim of achieving lower cost and higher cell efficiencies. The flexibility and simplicity of these photo-electrochemical systems has motivated significant research efforts in this field. Current efforts are focused on the utilization of alternative materials to replace the rather expensive platinum electrodes. The physical properties of the Iron-Copper system present an appealing choice as an alternative counter-electrode material. However, due the complexities in preparing metastable Fe-Cu alloys, the understanding of the fundamental electrical properties of this system remains limited and not fully understood. Developing a better understanding of the electrical properties of Fe-Cu, including composition dependencies, are relevant to the potential use of this alloy system in solar cell applications. In this work, FeᵪCu₁₀₀ ̱ᵪ alloys where x (wt%) = 25, 35, 50, 65, and 75 were prepared via mechanical alloying (MA) method. Microstructural characterization revealed a single-phase face-centered cubic structure for a wide range of compositions. Temperature dependencies of the resistivity were measured for all samples. At low temperatures, the Fe₂₅Cu₇₅ alloy exhibited T³⁄² dependence of the resistivity. At higher temperatures (100-300K) all of the mechanically alloyed Fe-Cu exhibited unusual T linear dependence resistivity. As for the magnetic properties, samples with Fe content higher than 35% exhibited magnetic transition temperatures (Tc) higher than 350K. The counter-electrode was manufactured by depositing Fe₅₀Cu₅₀ on an aluminum sheet using MA and rolling methods. Dye-sensitized cells were produced, assembled, and tested with both platinum electrodes and Al-Fe₅₀Cu₅₀ counter electrodes, resulting in maximum efficiencies of (3.7%) and (0.26%) respectively. Additionally, the efficiency-cost of these cells were investigated resulting in (0.25% per AED) for platinum electrode, and (3.0% per AED) for Al-Fe₅₀Cu₅₀ electrode. The obtained results indicate that it has a notable potential which warrants further research and optimization efforts.