Dye-Sensitized Solar Cells Using Aluminum-Doped Zinc Oxide/Titanium Dioxide Photoanodes in Parallel

• Main Authors: Jung-Chuan Chou, Cheng-Chu Ko, Jun-Xiang Chang, Chih-Hsien Lai, Yu-Hsun Nien, Po-Yu Kuo, Huang-Hua Chen, Hui-Hsuan Hsu, Geng-Ming Hu
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Energies
• Subjects: dye-sensitized solar cells (DSSCs); aluminum-doped zinc oxide (AZO); titanium dioxide (TiO₂); parallel connection
• Online Access: https://www.mdpi.com/1996-1073/12/18/3469

In this study, both zinc oxide (ZnO) nanorods and aluminum-doped zinc oxide (AZO) nanosheets were deposited by hydrothermal growth on fluorine-doped tin oxide (FTO) glass. After a photoanode was added to ZnO nanorods or AZO nanosheets, the photovoltaic conversion efficiency (PCE) increased due to improved electron transport and enhanced dye absorption. The improvement in electron transport was verified by electrochemical impedance spectroscopy (EIS), and the increase in dye absorption was verified by ultraviolet-visible spectroscopy. Both of these factors facilitated an increase in PCE. Parameters for dye-sensitized solar cells (DSSCs) using ZnO nanorods/TiO₂ and AZO nanosheets/TiO₂ photoanodes were tested and the results were recorded using EIS. The results indicated that the addition of the ZnO nanorods increased the short-circuit current density (<i>J_sc</i>) from 9.07 mA/cm² to 10.91 mA/cm², the open circuit voltage (<i>V_oc</i>) from 0.68 V to 0.70 V, and the PCE from 3.70% to 4.73%, respectively. When the DSSCs were produced in a parallel silver-grid device, the results showed that PCE could be increased from 3.67% to 4.04% due to the reduction in connection resistance.