Study of the optical and photovoltaic properties in nanoparticles of BiFeO₃

Bismuth ferrite ceramic powders (BiFeO₃) were synthesized by a combustion reaction in solution, using the mixture of urea and glycine as fuels, whose objectives were to improve their optical, electrical and photovoltaic response properties. X-ray diffraction analysis indicated the formation of the single phase BiFeO3. Transmission electron microscopy (TEM) shows images of uniform nanoparticles of 70 nm on average. Through diffuse reflectance we obtain a band gap with a direct electronic transition of 2.14 eV, this value presents an improvement compared to that reported by other authors in BiFeO₃ ceramic powders. The value of the resistivity obtained by the 4-pointed method was ρ = 0.486 × 106 Ω.cm, checking that our material is a semiconductor. Finally, by building a prototype of Ag/BiFeO₃/Ag, with visible light (λ = 405 nm), a photovoltaic response of 0.2 nA at room temperature was achieved.