High Humidity Response of Sol-Gel-Synthesized BiFeO3 Ferroelectric Film

In this work, a BiFeO3 film is prepared via a facile sol-gel method, and the effects of the relative humidity (RH) on the BiFeO3 film in terms of capacitance, impedance and current-voltage (I-V) are explored. The capacitance of the BiFeO3 film increased from 25 to 1410 pF with the increase of RH from 30% to 90%. In particular, the impedance varied by more than two orders of magnitude as RH varied between 30% and 90% at 10 Hz, indicating a good hysteresis and response time. The mechanism underlying humidity sensitivity was analyzed by complex impedance spectroscopy. The adsorption of water molecules played key roles at low and high humidity, extending the potential application of ferroelectric BiFeO3 films in humidity-sensitive devices.

Automated summary

A BiFeO3 film was prepared using a sol-gel method, and the effects of relative humidity on the film's capacitance, impedance, and current-voltage characteristics were explored. The capacitance of the film increased significantly from 25 to 1410 pF as the relative humidity increased from 30% to 90%. The impedance also varied greatly, indicating good hysteresis and response time. Analysis of the humidity sensitivity mechanism revealed the crucial role of water molecule adsorption at both low and high humidity, extending the potential applications of ferroelectric BiFeO3 films in humidity-sensitive devices.