학술논문
Iron alloying improved electrocatalytic activity of Cu2 Cu1−x Fex SnS4 counter electrodes in dye-sensitized solar cells
Document Type
Original Paper
Author
Source
Journal of Applied Electrochemistry. 54(4):757-766
Subject
Language
English
ISSN
0021-891X
1572-8838
1572-8838
Abstract
Nanocrystalline Cu2 Cu1−x Fex SnS4 (CCFTS) was prepared by a simple liquid-phase method. Physiochemical properties of the CCFTS powder as well as the CEs fabricated thereby were investigated using XRD, Raman spectroscopy, SEM, UV–Vis absorption, electrochemical impedance spectroscopy (EIS), etc. Conduction band shifts as well as the bandgap increases in the as-prepared CCFTS as a function of the Fe content were observed. For the dye-sensitized solar cells (DSSCs) with CCFTS counter electrodes (CEs), charge transfer impedance (Rct1 ) and short-circuit current (Jsc ) were reduced by 64.54% and improved by 14.64%, respectively, compared with that with Fe-free Cu3 SnS4 (CTS) CE. The enhancement of electron transfer through the CE/electrolyte interfaces stems from the optimal energy level alignment and the surface morphology tuned by the Fe alloying and hence improve the electrocatalytic activity of the CEs for the reduction from I3 − to I− . As a consequence, photovoltaic conversion efficiency (PCE) of 6.95% was obtained which is 1.25 times that of the cell with Fe-free CTS CE. This work confirmed that element alloying into nanocrystalline transition metal compounds is effective for catalytic activity improvement. Material preparation reported herein is feasible, has high efficiency and low cost, and believed beneficial to high DSSCs development.Graphical abstract: