Synthesis and characterization of barium zinc ferrite nanoparticles: Working electrode for dye sensitized solar cell applications

• Spinel type Zn1−xBaxFe2O4 nanoparticles were prepared by an auto combustion method.
• XRD confirms the phases in the Zn1−xBaxFe2O4 (x = 0. 01, 0.05, 0.10, 0.15) ferrite.
• Chemical composition and oxidation states were analyzed using XPS.
• The optical band gap values were determined from UV–DRS using Tauc relation.

Spinel type barium zinc ferrite (Zn1−xBaxFe2O4) nanoparticles with compositions of barium (x = 0.01–0.15) were prepared by an auto combustion method using glycine as fuel and nitrates as precursors. The formation mechanisms of these ferrite nanoparticles are briefly discussed. The prepared samples were characterized by powder X-ray Diffraction analysis (XRD) and confirm the formation of pure phase zinc ferrite with cubic structure. The average crystallite size was found to vary from 39.5 nm to 47.6 nm. X-ray Photoelectron Spectroscopy (XPS) was used to analyze the elemental composition and oxidation states of the elements in the ferrite samples. Detailed photoelectron peaks of Zn 2p, Fe 2p, O 1s and Ba 3d with corresponding binding energy are presented in the XPS spectrum. The optical band gap values increased from 2.42 eV to 2.50 eV with increase in barium concentration as determined from UV–Diffuse Reflectance Spectroscopy (DRS) using Tauc relation. The current–voltage (J–V) curve for DSSC based on barium zinc ferrite nanoparticles sensitized with Eosin yellowish dye was characterized by J–V measurements. It exhibited a maximum optimal energy conversion efficiency of around 0.0027% for barium doped zinc ferrite nanoparticles whereas the cell based on the pure zinc ferrite nanoparticles gave efficiency of approximately 0.0014% and enhanced open circuit voltage and current are obtained.