Abstract:
Electron transport layer is one of the important part in the dye-sensitized and perovskite solar cells
which is responsible for the transport of photo-generated electrons to the outer circuit. Thus, selection of
appropriate Electron transport layer (ETL) is important for attaining higher power conversion efficiency.
Localised surface plasmon resonance can be used as a strategy to improve the total light absorption and it
also has been reported that the metallic nanoparticles induce localized electric field, which can excite
dye/perovskite molecules more effectively than far-field light which would lead to enhanced light
absorption by the adsorbed dye/perovskite molecule which in turn would result in improved generation of
photo-excited electrons. In this work TiO2 nanoparticles were synthesized by a simple solvothermal method
and the Ag nanoparticles were decorated over TiO2 by photo deposition technique. The X-ray diffraction
analysis of the sample showed characteristic peaks for anatase phase of TiO2 and the Ag decorated TiO2
showed peaks corresponding to (200) planes of Ag nanoparticles. Optical properties were studied using
UV-visible absorption analysis and it showed strong absorption in the UV region for TiO2 and the surface
plasma resonance (SPR) effect is observed in Ag decorated samples. TEM analysis showed the presence of
near-spherical shape Ag nanoparticles which were present uniformly over TiO2 nanoparticles. XPS analysis
revealed the chemical states of the prepared material. For the constructed DSSC using the prepared
material, open circuit voltage (Voc) of 0.67 V and 0.69 V and efficiency (η) of 5.4 and 7.3 % were obtained
for bare TiO2 and Ag decorated TiO2 based solar cells respectively. A similar trend of enhanced performance
was observed for the Ag decorated TiO2 when compared to bare TiO2 when used as ETL layer in the case
of perovskite solar cells as well.
