The effect of TiO2 nanostructures such as nanoparticles, nanowires, nanotubes on photoanode properties, and dye-sensitized solar cells photovoltaic parameters were studied. The series of dye-sensitized solar cells based on two dyes, that is, commercially N719 and synthesized 3,7′-bis(2-cyano-1-acrylic acid)-10-ethyl-phenothiazine were tested. Additionally, the devices containing a mixture of this sensitizer and chenodeoxycholic acid as co-adsorbent were fabricated. The amount of adsorbed dye molecules to TiO2 was evaluated. The prepared photoanodes with different TiO2 nanostructures were investigated using UV-Vis spectroscopy, optical, atomic force, and scanning electron microscopes. Photovoltaic response of constructed devices was examined based on current-voltage characteristics and electrochemical impedance spectroscopy measurements. It was found that the highest UV-Vis absorption exhibited the photoanode with nanotubes addition. This indicates the highest number of sensitizer molecules anchored to the titanium dioxide photoanode, which was subsequently confirmed by dye-loading tests. The highest power conversion efficiency was (6.97%) for solar cell containing nanotubes and a mixture of the dyes with a co-adsorbent.
1 October 2007 in Journal of Materials Processing Technology
Since the forming of the microstructure depends on the specific of the casting method, which directly affects further mechanical and physical properties of the material, it is important to understand how to control the microstructure of the cast to understand changes that taking place during the crystallisation process. For estimating the metallurgical quality of the liquid metal before casting, the thermal-derivative analysis (TDA) is utilised. The TDA has been used for a long time, in both ferrous and non-ferrous industries casting. The Universal Metallurgical Simulator and Analyser (UMSA) platform is a rapid, sensitive and economical method of determining a full range of solidification features. The work focuses on the thermal analysis and heat treatment of aluminium alloys. The liquidus and solidus temperatures and dendrite coherency point (DCP) are then characterised. The research shows that the UMSA platform allows precise determination and calculation of thermal parameters. The influence of the heat treatment on structure and properties of aluminium castings has been determined as well. Heat treatment was carried out to increase the mechanical properties of aluminium alloys. Based on the findings above, the influence of microstructure on properties of the alloys is discussed.