Cetyltriammonium Bromide Assisted Synthesis of Lanthanum Containing Barium Stannate Nanoparticles for Application in Dye Sensitized Solar Cells.

In present work, correlation of structural and optical behavior of pristine and lanthanum containing barium stannate nanoparticles (synthesized via cetyltriammonium bromide (CTAB) assisted facile wet chemical route), and its effect on photovoltaic properties of dye‐sensitized solar cell are reported. Thermo‐gravimetric analysis of the dried compound presumably BaSn(OH)6, leads to the formation of BaSnO3 nanoparticles through three endothermic decomposition processes, via liberation of one mole of water in each step, together with removal of remaining CTAB in initial cycle. The X‐ray diffraction patterns reveal that substitution of Ba2+ lattice sites by La3+ (upto ≈6 at.%), the lattice retains its cubic Pm3m symmetry, however, unit cell contracts. The dye sensitized solar cells are fabricated using pristine and La‐ containing BaSnO3 as photo anode; platinum coated FTO as counter electrode, N719 dye as sensitizer and I−/I3− as electrolyte. These show the highest power conversion efficiency (≈9.2%) at the La content of 6 at.% which is about threefold increase in efficiency in comparison to pristine BaSnO3. The electron transport properties of these DSSC devices are investigated by electro chemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]