Fabrication of dye sensitized solar cells with different photoanode compositions using hydrothermally grown and P25 TiO₂ nanocrystals

¹ Physics Department, Faculty of Science, Arak University, 38156 Arak, Iran
² Chemical Engineering Department, Faculty of Engineering, Arak University, 38156 Arak, Iran

^a email: m-marandi@araku.ac.ir

Received: 21 September 2014
Revised: 14 December 2014
Accepted: 13 January 2015
Published online: 25 February 2015

Abstract

In this research P25 TiO₂ nanoparticles (NPs) and hydrothermally grown TiO₂ nanocrystals (NCs) were used in the photoanode of the dye sensitized solar cells. The dominant size of hydrothermally grown TiO₂ NCs was about 20 nm. Different photoanode compositions including various weight percents of different NCs were prepared. The photoelectrodes demonstrated a light scattering which was strongly dependent on the weight percent of P25 TiO₂ NPs. According to the results, when the photoanode was dominantly composed of hydrothermally grown TiO₂ NCs, the dye sensitized solar cells represented acceptable efficiencies. For the weight percent ratios of 70/30 and 30/70 for hydrothermally grown to P25 TiO₂ NPs the efficiency was considerably decreased. This was specially observed for the thicker photoelectrodes. Nevertheless, when the photoanode was composed of equal weight percents of different NCs (50/50), the maximum efficiency of 7.1% was achieved. This was addressed due to the optimum situation of light scattering, dye adsorption and minimum of the tension in photoanode layer.