Electrochemical and structural analysis of Al-doped ZnO nanorod arrays in dye-sensitized solar cells

• Published in: Journal of power sources Vol. 214; pp. 159 - 165
• Main Authors: Tao, Runbang, Tomita, Takahiro, Wong, Raymond Albert, Waki, Keiko
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-09-2012; Elsevier
• Subjects: Al-doped ZnO nanorod arrays; Aluminum; Applied sciences; Arrays; Dye-sensitized solar cells; Electric potential; Energy; Exact sciences and technology; Increase in open-circuit voltage; Morphological; Nanocomposites; Nanomaterials; Nanostructure; Natural energy; Photovoltaic conversion; Reduction (electrolytic); Solar cells. Photoelectrochemical cells; Solar energy; Structural changes; Zinc oxide; Increase in open-circuit voltage; Structural changes; Dye-sensitized solar cells; Morphological; Al-doped ZnO nanorod arrays; Performance evaluation; Structural design; Dye-sensitized solar cell; Electrochemical analysis; Short circuit currents; II-VI compound; Electrical properties; Doping; Electrode electrolyte interface; Doped materials; Aluminium addition; Open circuit voltage; Charge carrier recombination; Morphology; Zinc oxide; Nanorod; Structural analysis; Electrical characteristic
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.04.071

Al-doped ZnO nanorod arrays with the Al contents in the region of 0–5% were prepared and evaluated as photoanodes for dye-sensitized solar cells (DSSCs). It was found that Al-doping has changed not only electrical properties but also the morphology and structure of the ZnO nanorods. The open-circuit voltage increased significantly with the addition of Al, up from 0.636 V to 0.732 V, due to the increase in electron recombination resistance at the ZnO nanorod array electrode/electrolyte interfaces resulting in the reduction in dark current. The diameter of the ZnO nanorods also changes with the addition of Al. Our results indicate that an appropriate increase in the diameter of the nanorods is favorable due to the reduction in electron transport resistance, which further speeds up electron transport in the ZnO nanorod arrays leading to the increase of short-circuit current. Of the samples analyzed, the DSSC containing Al-doped ZnO nanorod arrays of 0.5% exhibits the highest efficiency due to its increased open-circuit voltage and short-circuit current.
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► Al-doped ZnO nanorod arrays for photoanode for dye-sensitized solar cells. ► The open-circuit voltage increased significantly with the addition of Al, up from 0.636 V to 0.732 V ► Diameter of nanorods changed with the addition of Al. ► Appropriate increase in nanorod diameter is considered favorable for performance.