| 초록 |
CoxNi1-x alloys (0 ≤ x ≤ 1) are successfully synthesized and immobilized on a reduced graphene oxide (RGO) surface using the dry plasma reduction method. High-resolution scanning electron microscopy (HRSEM) and X-ray photoelectron spectroscopy (XPS) measurements are used to analyze the morphology and chemical composition of the developed materials. Then, the developed materials are applied as efficient Pt-free counter electrodes (CEs) in dye-sensitized solar cells (DSCs). In order to obtain efficient CEs, the chemical composition of the CoxNi1-x/RGO is controlled through optimizing the volume ratio of the Co and Ni precursors during the synthesizing process. It is found that the highest efficiency was 6.75% for the device using Co0.3Ni0.7/RGO CE, which is also higher than those of the devices using Pt CE (6.63%), Co/RGO (6.33%), and Ni/RGO (5.52%). The obtained results can be explained through the optimization of the charge-transfer resistance (Rct) and diffusion impedance (Zw) values of the developed materials. The strategy is simple and efficient; thus, it is promising for fabricating highly efficient and low-cost CE materials for DSCs. |
