Optimization of processing parameters on the controlled growth of ZnO nanorod arrays for the performance improvement of solid-state dye-sensitized solar cells

• Published in: Journal of solid state chemistry 2011-03, Vol.184 (3), p.615-623
• Main Authors: Lee, Yi-Mu, Yang, Hsi-Wen
• Format: Article
• Language: English
• Subjects: Arrays; ASPECT RATIO; CHALCOGENIDES; Chemical bath deposition; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; CRYSTAL GROWTH; CURRENTS; DEPOSITION; DIMENSIONLESS NUMBERS; DIRECT ENERGY CONVERTERS; DISPERSIONS; DYES; ELECTRIC CURRENTS; ELECTRICAL PROPERTIES; Exact sciences and technology; Heterojunction electrode; HETEROJUNCTIONS; HOMOGENEOUS MIXTURES; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LEAKAGE CURRENT; Materials science; Methods of crystal growth; physics of crystal growth; Methods of nanofabrication; MIXTURES; Nanocomposites; Nanomaterials; Nanorod arrays; Nanoscale materials and structures: fabrication and characterization; Nanostructure; NICKEL COMPOUNDS; NICKEL OXIDES; OPACITY; OPTICAL PROPERTIES; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; OPTIMIZATION; OXIDES; OXYGEN COMPOUNDS; PHOTOELECTRIC CELLS; PHOTOVOLTAIC CELLS; PHYSICAL PROPERTIES; Physics; Process parameters; Quantum wires; SEMICONDUCTOR JUNCTIONS; SOLAR CELLS; SOLAR EQUIPMENT; SOLUTIONS; TEMPERATURE RANGE; TEMPERATURE RANGE 0273-0400 K; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; TRANSITION ELEMENT COMPOUNDS; ZINC COMPOUNDS; Zinc oxide; ZINC OXIDES; ZnO
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2011.01.021

High-transparency and high quality ZnO nanorod arrays were grown on the ITO substrates by a two-step chemical bath deposition (CBD) method. The effects of processing parameters including reaction temperature (25–95 °C) and solution concentration (0.01–0.1 M) on the crystal growth, alignment, optical and electrical properties were systematically investigated. It has been found that these process parameters are critical for the growth, orientation and aspect ratio of the nanorod arrays, showing different structural and optical properties. Experimental results reveal that the hexagonal ZnO nanorod arrays prepared under reaction temperature of 95 °C and solution concentration of 0.03 M possess highest aspect ratio of ∼21, and show the well-aligned orientation and optimum optical properties. Moreover the ZnO nanorod arrays based heterojunction electrodes and the solid-state dye-sensitized solar cells (SS-DSSCs) were fabricated with an improved optoelectrical performance. The ZnO nanorod arrays demonstrate well-alignment, high aspect ratio ( L/ D∼21) and excellent optical transmittance by low-temperature chemical bath deposition (CBD). [Display omitted] ► Investigate the processing parameters of CBD on the growth of ZnO nanorod arrays. ► Optimization of CBD process parameters: 0.03 M solution concentration and reaction temperature of 95 °C. ► The prepared ZnO samples possess well-alignment and high aspect ratio ( L/ D∼21). ► An n-ZnO/p-NiO heterojunction: great rectifying behavior and low leakage current. ► SS-DSSC has J SC of 0.31 mA/cm 2 and V OC of 590 mV, and an improved η of 0.059%.