Research On Barium Titanate Ferroelectric Thin Film Materials And Sensors

Currently,the development of a new generation of intelligent electronic products based on the Internet of Things requires the integration of various functions with traditional electronic systems.Flexible self-actuated electronic products have been attracting people’s attention in today’s energy-hungry world due to their advantages of portability,bendability,light weight and friendly human-computer interface.However,it remains a great challenge to integrate multiple functions into a single flexible self-driven electronic device in a cost-effective and non-polluting manner.In recent years,ferroelectric photovoltaic materials have attracted much attention due to their tunable current and voltage above band gap.In this paper,a multifunctional flexible electronic device with lanthanum nickelate as the bottom electrode,barium titanate ferroelectric film as the acting layer,and indium oxide as the top electrode was successfully prepared on mica by sol-gel method,and its structure,morphology,optical and ferroelectric properties were characterized in detail.Then the electrical signals generated by the device under different light conditions were systematically investigated,and it was found that the device produced different current signals under different wavelengths of laser light,i.e.,photovoltaic currents under near-UV light and pyroelectric currents under near-IR light.The study of the photovoltaic properties of ferroelectric materials reveals that this wavelength-induced current property is related to the polarization of ferroelectric materials and allows the device to recognize both the power and wavelength of light.Based on this property,this paper designs five optoelectronic logic gates,allowing it to perform the functions of five logic gates:with,or,with/without,or without,and without gates.In addition,this paper investigates the pyroelectric signal generated by the device at different temperature variations and its output performance as a pyroelectric nanogenerator,and finds that the pyroelectric current generated by the device and the amount of transferred charge show a good linear relationship with the degree of temperature variation,At the peltier operating voltage of 7 V and a load resistance of 32.5 MΩ,the device can achieve a maximum output power of 1.13 m W/m~2.This paper also investigates the bending resistance of the device.After10,000 times of bending at an angle of 40 degrees,the device retains more than ninety percent of its performance.These results indicate that the device can be used as a multifunctional self-driven flexible electronic device integrating photoelectric sensor,temperature sensor,and pyroelectric nanogenerator,which is expected to be applied in portable wearable electronic devices,human-computer interaction system,optical communication,intelligent agriculture,and robotic skin.This work expands the application area of ferroelectric thin film materials and provides new ideas for designing ferroelectric materials for flexible electronic devices.