Highly textured freestanding PZT membranes with enhanced dielectricity and ferroelectricity.

Pb(Zr,Ti)O3 (PZT) is one of the most widely used ferroelectric oxides and its freestanding membranes are always plausible for developing advanced capacitors, sensors, and actuators for flexible electronics. Freestanding single-crystalline PZT membranes are ideal for applications but rely on specific single-crystalline oxide substrates. The electric properties of textured PZT thin films are close to those of single-crystalline ones; however, flexible PZT membranes with controlled orientations are seldom reported. Here, both (111)- and (100)-textured freestanding PbZr0.4Ti0.6O3 films were fabricated using an optimized seed/sacrificial layer method on commonly used platinized silicon substrates. While freestanding (111)-textured films could be released using La0.7Sr0.3MnO3 as a sacrificial layer, freestanding (100)-textured films are released by additionally introducing PbO/PZT as a seed layer below La0.7Sr0.3MnO3. The freestanding (100)-textured films exhibit enhanced ferroelectric properties with spontaneous polarization up to 53 μC cm-2 and maintain stable polarization performance under mechanical bending. Such highly textured flexible films show great promise for applications in smart actuators and sensors.