摘要
Vertical ZnO nanotube (ZNT) arrays were synthesized onto an indium doped tin oxide (ITO) glass substrate by a simple electrochemical deposition technique followed by a selective etching process. Scanning electron microscopy (SEM) showed formation of well-faceted hexagonal ZNT arrays spreading uniformly over a large area. X-ray diffraction (XRD) of ZNT layer showed substantially higher intensity for the (0002) diffraction peak, indicating that the ZnO crystallites were well aligned with their c-axis. Profilometer measurements of the ZNT layer showed an average thickness of -7 μm. Diameter size distribution (DSD) analysis showed that ZNTs exhibited a narrow diameter size distribution in the range of 65-120 nm and centered at -75 nm. The photoluminescence (PL) spectrum measurement showed violet and blue luminescence peaks that were centered at 410 and 480 nm, respectively, indicating the presence of internal defects. Ultra-violet (UV) spectroscopy showed major absorbance peak at ,-348 nm, exhibiting an increase in energy gap value of 3.4 eV. By employing the formed ZNTs as the photo-anode for a dye-sensitized solar cell (DSSC), a full-sun conversion efficiency of 1.01% was achieved with a fill factor of 54%. Quantum efficiency studies showed the maximum of incident photon-to-electron conversion efficiency in a visible region located at 590-550 nm range.
Vertical ZnO nanotube (ZNT) arrays were synthesized onto an indium doped tin oxide (ITO) glass substrate by a simple electrochemical deposition technique followed by a selective etching process. Scanning electron microscopy (SEM) showed formation of well-faceted hexagonal ZNT arrays spreading uniformly over a large area. X-ray diffraction (XRD) of ZNT layer showed substantially higher intensity for the (0002) diffraction peak, indicating that the ZnO crystallites were well aligned with their c-axis. Profilometer measurements of the ZNT layer showed an average thickness of -7 μm. Diameter size distribution (DSD) analysis showed that ZNTs exhibited a narrow diameter size distribution in the range of 65-120 nm and centered at -75 nm. The photoluminescence (PL) spectrum measurement showed violet and blue luminescence peaks that were centered at 410 and 480 nm, respectively, indicating the presence of internal defects. Ultra-violet (UV) spectroscopy showed major absorbance peak at ,-348 nm, exhibiting an increase in energy gap value of 3.4 eV. By employing the formed ZNTs as the photo-anode for a dye-sensitized solar cell (DSSC), a full-sun conversion efficiency of 1.01% was achieved with a fill factor of 54%. Quantum efficiency studies showed the maximum of incident photon-to-electron conversion efficiency in a visible region located at 590-550 nm range.
基金
Department of Science and Technology (DST), Government of India was gratefully acknowledged for their financial support under the NATAG program monitored by Dr. G. Sundararajan