Ji Xuan, Zhang Maolin, Zhang Dongyan, Wang Yuan, Huang Yunxia, Yan Yangxi, Sun Peng, Li Zhimin
School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, 710071, China.
J Nanosci Nanotechnol. 2019 Aug 1;19(8):5338-5343. doi: 10.1166/jnn.2019.16830.
The counter electrode (CE) with high catalytic activity has been vital to improve photovoltaic performance of quantum dot sensitized solar cells (QDSSCs). Cobalt selenide has been proved to have outstanding electrocatalytic activity among the electrode materials. In this work, CoSe films were directly deposited on the F doped SnO₂ glass (FTO) substrate by one-step solvothermal method. The film phase and microstructure were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM), respectively. Further, the effects of starting reactant concentration on the uniformity and continuity of CoSe films were determined by scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). Then, QDSSCs with CoSe film as CE and CdS/CdSe/TiO₂ film as photoanode obtained a power conversion efficiency of 2.4%, which exceeded reported efficiency by 14%. Electrochemical impedance spectra (EIS) and Tafel-polarization measurements indicated that the enhanced performance was attributed to the superior catalytic activity and high diffusion coefficient at the interface between CoSe CE and polysulfide electrolyte.
具有高催化活性的对电极（CE）对于提高量子点敏化太阳能电池（QDSSC）的光伏性能至关重要。硒化钴已被证明在电极材料中具有出色的电催化活性。在这项工作中，通过一步溶剂热法将CoSe薄膜直接沉积在F掺杂的SnO₂玻璃（FTO）基板上。分别用X射线衍射（XRD）和高分辨率透射电子显微镜（TEM）对薄膜相和微观结构进行了表征。此外，通过扫描电子显微镜（SEM）和能量色散光谱仪（EDS）确定了起始反应物浓度对CoSe薄膜均匀性和连续性的影响。然后，以CoSe薄膜为CE、CdS/CdSe/TiO₂薄膜为光阳极的QDSSC获得了2.4%的功率转换效率，比报道的效率高出14%。电化学阻抗谱（EIS）和塔菲尔极化测量表明，性能的提高归因于CoSe CE与多硫化物电解质界面处的优异催化活性和高扩散系数。
