Direct Growth of Ferroelectric Oxide Thin Films on Polymers through Laser-Induced Low-Temperature Liquid-Phase Crystallization

The outstanding multifunctionality of ferroelectric oxides has opened up new fields in microelectronics. However, the high crystallization temperature of the ferroelectric oxides limits their integration into functional platforms, such as flexible polymers. Here, the direct synthesis of the ferroelectric oxide thin films on the flexible polymer platforms is demonstrated. A new growth mechanism for the oxide thin film, named laser-activated liquid phase crystallization, has been discovered, which facilitates the ultrafast low-temperature crystallization of the ferroelectric PbZr0.52Ti0.48O3 (PZT) thin film. Through this mechanism, a homogeneous crystalline PZT thin film is obtained on a flexible polyimide substrate at 200 °C. The flexible PZT film is found to exhibit outstanding ferroelectric and piezoelectric properties along both the in-plane and out-of-plane direction. Exploiting the flexible PZT thin film, flexible ferroelectric capacitors and piezoelectric sensors are demonstrated. The findings of this study provide new functions in flexible electronics and shall pave the way for entirely new applications.