Guiding and capturing photons at the nanoscale by means of metal nanoparticles and interfacial engineering for preventing back-electron transfer are well documented techniques for performance enhancement in excitonic solar cells. Drifting from the conventional route, we propose a simple one-step process to integrate both metal nanoparticles and surface passivation layer in the porous photoanode matrix of a dye-sensitized solar cell. Silver nanoparticles and NbO surface passivation layer are simultaneously deposited on the surface of a highly porous nanocrystalline TiO photoanode, facilitating an absorption enhancement in the 465 nm and 570 nm wavelength region and a reduction in back-electron transfer in the fabricated dye-sensitized solar cells together. The TiO photoanodes were prepared by spray pyrolysis deposition method from a colloidal solution of TiO nanoparticles. An impressive 43% enhancement in device performance was accomplished in photoanodes having an Ag-incorporated NbO passivation layer as against a cell without Ag nanoparticles. By introducing this idea, we were able to record two benefits - the metal nanoparticles function as the absorption enhancement agent, and the NbO layer as surface passivation for TiO nanoparticles and as an energy barrier layer for preventing back-electron transfer - in a single step.
S. Suresh, Unni, G. E., Satyanarayana, M., A Nair, S., and Pillai, V. P. Mahadeva, “Silver nanoparticles-incorporated NbO surface passivation layer for efficiency enhancement in dye-sensitized solar cells.”, J Colloid Interface Sci, vol. 524, pp. 236-244, 2018.