Co-sensitization of quantum dot sensitized solar cells composed of TiO2 nanocrystalline photoanode with CdS and PbS nanoparticles and effect of PbS on the performance of solar cell

In this research, CdS and PbS quantum dots were applied as the light sensitizers in TiO2 based nanostructured solar cells. The PbS quantum dots could absorb a wide range of the sunlight spectrum on earth due to their low bandgap energy. As a result, the cell sensitization is more effective by application of both CdS and PbS quantum dots sensitizers. The TiO2 nanocrystals were synthesized through a hydrothermal process and deposited on FTO glass substrates as the photoanode scaffold. Then PbS quantum dots were grown on the surface of this nanocrystalline layer by a successive ionic layer adsorption and reaction (SILAR) method. The CdS quantum dots were over-grown in the next step through a similar deposition method. Finally this sensitized layer was applied as the photoelectrode of the corresponding quantum dot sensitized solar cells. The results demonstrated that the maximum efficiency was achieved for the cell with a photoanode made of co-sensitization through 2 and 6 cycles of PbS and CdS deposition, respectively. The photovoltaic parameters of this cell were measured as Jsc of 10.81 mA/cm2, Voc of 590 mv and energy conversion efficiency of 2.7+0.2%

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

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

Fabrication of dye sensitized solar cells with different photoanode compositions using hydrothermally grown and P25 TiO 2

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