Increased efficiency of dye-sensitized solar cells by addition of rare earth oxide microparticles into a titania acceptor.

The addition of 400 micron scale rare-earth metal oxide particles to the TiO 2 nanoparticle acceptor layer of a dye-sensitized solar cell (DSSC) dramatically increases the efficiency of the solar cell by 10-30%. Oxidized neodymium powder, Nd 2 O 3 , combined with TiO 2 nanoparticles forms a composite photoanode containing a wide range of Nd 2 O 3 particle sizes. Based on absorbance measurements, the dye-uptake on the Nd 2 O 3 /TiO 2 anode increases substantially compared to both a standard anode and to one made from a mixture of large and small TiO 2 particles. Electrochemical impedance spectroscopy (EIS) shows a similar electron lifetime, but increased electron transport diffusion coefficient through the Nd 2 O 3 /TiO 2 composite as compared to TiO 2 only. This shows that the Nd 2 O 3 /TiO 2 composite has a lower internal resistance for charge transport. This decrease in resistance, possibly due to the filling of trap states by the Nd 2 O 3 valence or f-states, and increased dye uptake results in improved efficiency by simple incorporation of Nd 2 O 3 powder. [ABSTRACT FROM AUTHOR]