Abstract：
In piezoelectric transducer applications, it is common to use a unipolar operation signal to avoid switching of the polarisation and the resulting nonlinearities of micro-electromechanical systems. However, semi-bipolar or bipolar operation signals have the advantages of less leakage current, lower power consumption and no additional need of a DC-DC converter for low AC driving voltages. This study investigates the potential of using piezoelectric layers with an imprint for stable bipolar operation on the basis of epitaxially grown lead zirconate titanate cantilevers with electrodes made of a metal and metal oxide stack. Due to the manufacturing process, the samples exhibit high crystallinity, rectangular shaped hysteresis and a high piezoelectric response. Furthermore, the piezoelectric layers have an imprint, indicating a strong built-in field, which shifts the polarisation versus electric field hysteresis. To obtain the stability of the imprint, laser doppler vibrometry and switching current measurements were performed at different temperatures, yielding a stable imprinted electric field of -1.83 MV/m up to at least 100 °C. The deflection of the cantilevers was measured with a constant AC driving voltage while varying the DC bias voltage to examine the influence of the imprint under operation, revealing that the same high deflection and low nonlinearities, quantified by the total harmonic distortion, can be maintained down to low bias voltages compared to unipolar operation. These findings demonstrate that a piezoelectric layer with a strong imprint makes it possible to operate with low DC or even zero DC bias, while still providing strong piezoelectric response and linear behaviour.
摘要：
在压电换能器应用中，通常使用单极操作信号来避免微机电系统的极化和由此产生的非线性的切换。然而,半双极或双极工作信号具有漏电流小的优点，更低的功耗,并且对于低AC驱动电压不需要DC-DC转换器。这项研究研究了在外延生长的锆钛酸铅悬臂的基础上，使用带有压印的压电层进行稳定双极操作的潜力，该悬臂具有由金属和金属氧化物堆叠制成的电极。由于制造过程，样品表现出高结晶度，矩形磁滞和高压电响应。此外，压电层具有印记，表明一个强大的内置场，它改变了极化与电场滞后的关系。为了获得稳定的印记，在不同温度下进行激光多普勒测振和开关电流测量，在至少100°C下产生-1.83MV/m的稳定压印电场。用恒定的交流驱动电压测量悬臂的挠度，同时改变直流偏置电压，以检查工作时压印的影响。揭示了相同的高挠度和低非线性，由总谐波失真量化，与单极操作相比，可以保持低偏置电压。这些发现表明，具有强大印记的压电层可以在低DC甚至零DC偏置下运行，同时仍然提供强大的压电响应和线性行为。
