Effect of precursor pH value on the structure and electrical properties of Bi1.5Zn1.0Nb1.5O7 thin films

Bi 1.5 Zn 1.0 Nb 1.5 O 7 (BZN) thin films are synthesized on a FTO (Fluorine -doped SnO 2 transparent conductive glass) substrate by an improved sol-gel method. The pH of the precursor is controlled by citric acid and ammonia, and the effect of pH on the crystal structure and electrical properties of the BZN films is studied. When the precursor pH is 5, the relative intensity of the diffraction peak of BZN films is the highest, the FWHM is the narrowest, and the crystallization degree is the highest, compared to those of BZN films synthesized from precursors at other pH, the crystallization energy offset of the element binding energy of the thin films is the smallest and the phase difference of the binding energy is the closest to the theoretical value, and the films have excellent electrical properties with permittivity of 120, loss tangent of 0.003, tunability of 14.8%, breakdown voltage of 0.43 MV/cm and energy storage density of 9.82 × 10 −2  J/cm 3 .