Size-controllable synthesis of NiCoSe2 microspheres as a counter electrode for dye-sensitized solar cells

Xiaobo Chen; Jingguo Ding; Yan Li; Yinxia Wu; Guoce Zhuang; Cuicui Zhang; Zhihai Zhang; Chengyun Zhu; Peizhi Yang

doi:10.1039/c8ra04091e

Size-controllable synthesis of NiCoSe₂ microspheres as a counter electrode for dye-sensitized solar cells

RSC Adv. 2018 Jul 19;8(46):26047-26055. doi: 10.1039/c8ra04091e.

Authors

Xiaobo Chen¹, Jingguo Ding¹, Yan Li¹, Yinxia Wu¹, Guoce Zhuang¹, Cuicui Zhang¹, Zhihai Zhang¹, Chengyun Zhu¹, Peizhi Yang²

Affiliations

¹ School of New Energy and Electronic Engineering, Yancheng Teachers University Yancheng 224051 PR China chenxbok@126.com.
² Key Laboratory of Education Ministry for Advance Technique and Preparation of Renewable Energy Materials, Institute of Solar Energy, Yunnan Normal University Kunming 650500 PR China pzhyang@hotmail.com.

Abstract

NiCoSe₂ microspheres have been successfully synthesized by a facile one-step hydrothermal method at different hydrothermal temperatures. The prepared samples are divided according to their reaction temperatures (90, 120, 150 and 180 °C) and named NiCoSe₂-90, NiCoSe₂-120, NiCoSe₂-150 and NiCoSe₂-180, respectively. The diameters of the NiCoSe₂ microspheres strongly depend on the different hydrothermal temperatures. When the temperature is increased to 150 °C, the size of the resultant NiCoSe₂ microspheres changes from 200 to 800 nm, and the interior of NiCoSe₂-150 possesses a flocculent structure. However, NiCoSe₂-180 displays a cauliflower-like aggregated structure. The prepared NiCoSe₂ alloys are used as high-performance Pt-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). Cyclic voltammogram measurement indicates that NiCoSe₂-150 CE has larger current density than Pt CE. Electrochemical impedance spectroscopy shows that NiCoSe₂-150 CE has a low charge-transfer resistance of 1.8 Ω cm². Due to their unique morphologies and well-defined interior and exterior structures, DSSCs based on NiCoSe₂-120 and NiCoSe₂-150 CEs achieve high power conversion efficiencies of 8.48% and 8.76%, respectively, which are higher than that of the solar cell based on Pt CE (8.31%).