A Study On Platinum-Free And Efficient Counter Electrode In Dye-Sensitized Solar Cells

Platinum has attracted more attention as counter electrode in dye-sensitized solar cells(DSCs) due to its higher conductivity and superior catalytic activity. However, platinum metal is expensive and unstable in electrolyte containing iodine. Thus, developing platinum-free and low-cost counter electrode is urgent. Meanwhile, conducting glass substrates is fragile, expensive, and poor adaptability so as not to further application in solar cells.We have synthesized PPy/RGO counter electrode via simple two-steps electrochemical methods. This composites can avoid aggregation of PPy nanoparticles and graphene, so as to increase electrochemical catalytic activity sites and conductivity. The three-dimentional structure can accelerate diffusion of electrolyte so as to enhance catalytic performance of counter electrode. Cylic voltammetry and Electrochemical impedance tests have improved superior electrocatalytic activity as well as small charge-transfer resistance of PPy/RGO. Photoelectrical test demonstrates that the power conversion efficiency are 6.45% and 4.37% when deposited on FTO glass and ITO/PEN substrates, respectively.At the same time, we have prepared N-doped amorphous carbon/TiN/TiC counter electrode on Titanium foil using chemical vapor deposition method. This method not only achieved FTO replacement, but also avoided transfer of catalytic materials. Cylic voltammetry and Electrochemical impedance tests indicate that our counter electrode have superior electrochemical catalytic activity, outstanding cycling stability, adhesiveness and smaller charge-transfer resistance. The DSCs have obtained high power convention efficiency of 6.24% and 4.37% when applied this counter electrode in rigid and flexible solar cells.This article has investigated two kinds of counter electrode materials through simple fabrication methods. The two counter electrodes have reduce the production cost as well as improved catalytic activity which Path a new way for exploring new efficiency counter electrode materials.