| Abstract |
| This study examined the stability of a Cu/Pt bilayered counter electrode (CE) with the electrolyte and the energy conversion efficiency of dye-sensitized solar cells using a 0.45 cm2 dye-sensitized solar cell (DSSC) device with a glass/FTO/blocking layer/TiO2/N719 (dye)/electrolyte/50 nm-Pt/50 nm-Cu/FTO/glass. For comparison, a 100 nm-thick Pt only CE DSSC was also prepared using the same method. The photovoltaic properties, such as the short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), energy conversion efficiency (ECE), and impedance, were checked using a solar simulator and potentiostat with time after assembling the DSSC. The microstructure of the Cu/Pt bilayer was examined by optical microscopy after 0~30 minutes and 3 weeks. The ECE of the DSSC using the Pt only CE was 4.60 %, which did not show any time dependence. On the other hand, for the Cu/Pt CE DSSC, the ECEs after 0 minutes, 30 minutes, and 3 weeks were 5.72%, 5.03%, and 1.36%, respectively. Moreover, the interface resistance increased; 6, 7, and 40 Ω at 0 minutes, 30 minutes, and 3 weeks, respectively. The corrosion area of the Cu/Pt CE determined by an optical microscopy after 0 minutes, 30 minutes, and 3 weeks was 0, 23.40, and 51.35%, respectively. These results confirmed that the ECE and catalytic activity of Cu/Pt CE decreased drastically with time. Therefore, a DSSC using a Cu/Pt CE may be superior to the Pt only CE immediately after integrating of the device, but the performance of the former degrades drastically with time. †(Received September 30, 2013) |
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| Key Words |
| solar cells, sputtering, optical properties, solar simulator, bilayer |
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