Investigation of Coral-Like Cu2O Nano/Microstructures as Counter Electrodes for Dye-Sensitized Solar Cells

Materials

Chih-Hung Tsai¹  Po-Hsi Fei²  Chih-Han Chen²  Federico Bella² 

[1] Department of Opto-Electronic Engineering, National Dong Hwa University, Hualien 97401, Taiwan;

关键词: dye-sensitized solar cells;    cuprous oxide;    counter electrode;    nanostructures;   

DOI  :  10.3390/ma8095274

来源: mdpi

【 摘 要 】

In this study, a chemical oxidation method was employed to fabricate coral-like Cu₂O nano/microstructures on Cu foils as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The Cu₂O nano/microstructures were prepared at various sintering temperatures (400, 500, 600 and 700 °C) to investigate the influences of the sintering temperature on the DSSC characteristics. First, the Cu foil substrates were immersed in an aqueous solution containing (NH₄)₂S₂O₈ and NaOH. After reacting at 25 °C for 30 min, the Cu substrates were converted to Cu(OH)₂ nanostructures. Subsequently, the nanostructures were subjected to nitrogen sintering, leading to Cu(OH)₂ being dehydrated into CuO, which was then deoxidized to form coral-like Cu₂O nano/microstructures. The material properties of the Cu₂O CEs were comprehensively determined using a scanning electron microscope, energy dispersive X-ray spectrometer, X-ray diffractometer, Raman spectrometer, X-ray photoelectron spectroscope, and cyclic voltameter. The Cu₂O CEs sintered at various temperatures were used in DSSC devices and analyzed according to the current density–voltage characteristics, incident photon-to-current conversion efficiency, and electrochemical impedance characteristics. The Cu₂O CEs sintered at 600 °C exhibited the optimal electrode properties and DSSC performance, yielding a power conversion efficiency of 3.62%. The Cu₂O CEs fabricated on Cu foil were generally mechanically flexible and could therefore be applied to flexible DSSCs.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.