Synthesis of PtSe catalysts using atmospheric-pressure plasma and their application as counter electrodes for liquid-junction photovoltaic devices

Abstract

This study reports on the synthesis of PtxSe1-x(0 ≤ x ≤ 1) nanoparticles (NPs) with different volume ratios of Pt and Se in mixed precursor solutions on a transparent conducting oxide electrode using dry plasma reduction (DPR). DPR can work under atmospheric pressure without the use of any toxic chemicals and at a low temperature. The developed PtxSe1-x(0 ≤ x ≤ 1) NPs immobilized on FTO glass substrates were first employed to the counter electrodes (CEs) for efficient dye-sensitized solar cells (DSCs). The morphology and trends of PtxSe1-x(0 ≤ x ≤ 1) NPs were observed by scanning electron microscope (HRSEM) and transmission electron microscope (TEM), while varying the ratio of platinum to selenium precursor. In addition, physical and chemical characteristics of PtxSe1-x(0 ≤ x ≤ 1) NPs were analyzed by photoelectron spectroscopy (XPS). Electrochemical properties for the catalytic activity of CEs were also measured and analyzed by Tafel, Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). As a result, the CE prepared at the volume ratio of Pt0.9Se0.1 exhibits the lowest charge transfer resistance of 0.85Ω. Therefore, the device fabricated with Pt0.9Se0.1 alloy electrode shows the highest efficiency of 5.91% among all cells. This is also higher than the efficiency rates of 5.54% and 0.13% for cells fabricated with Pt NP and Se NP CEs, respectively. The obtained results indicate the potential use of PtSe alloy CEs in robust and efficient DSCs.