Synthesize of aluminum zinc oxide nanowires for dye sensitized solar cell application

• Main Author: Noorikalkenari, Hassan
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: QC Physics
• Online Access: http://eprints.utm.my/id/eprint/79313/1/HassanNoorikalkenariPFS2017.pdf; http://eprints.utm.my/id/eprint/79313/

Zinc oxide nanowires (ZnO NWs) have evoked extensive attention in recent years because of their potential technological applications. Aluminum (Al-ZnO) doped ZnO NWs have been deposited onto indium tin oxide (ITO) glass substrate, by using sol-gel spin coating and hydrothermal methods. Al-ZnO NWs with the percentage of Al content up to 6% were annealed at 450–600 °C. The structural, electrical and optical properties of the samples were characterized with X-ray diffraction (XRD), Energy-dispersive X-ray (EDX) spectroscope, Field-emission scanning electron microscope (FE-SEM), atomic force microscope (AFM), and UV-Visible spectrophotometer and photoluminescence (PL) spectrometer. Meanwhile, the Al-ZnO NWs conductivity level was determined by Van der Pauw method. XRD analysis confirmed a single phase spinel structure with the crystallite size between 20-50 nm calculated using the Scherrer’s formula. The highest main diffraction peak corresponding to the (002) orientation was due to the dominant phase of Al-ZnO at annealing temperature of 550 °C. The FE-SEM and AFM micrographs displayed the formation of well-defined and homogenous crystallite grains. The biggest grain size of 37 nm was observed for Al-ZnO NWs prepared with 6% Al concentration and annealed at 550 °C. The samples showed a high transmittance of more than 85% in the visible region, with energy band gap in the range of 3.25 to 3.35 eV. In addition, the electrical measurement result of the Al-ZnO NWs showed the lowest conductivity value of 2.49×10-4 S/cm with the activation energy Ea = 27 meV. A dye sensitized solar sell (DSSC) with this design showed a high short-circuit current density of 3.94 mA/cm2 and open circuit voltage of 0.48 V. A DSSC with efficiency of 0.72% was achieved using this photo-anode.