Piezoelectric materials are promising for pressure sensors in a variety of industrial applications such as automotive and petroleum fields. Typical piezoelectric sensors rely heavily on lead zirconate titanate (Pb[Zr_xTi_1-x]O₃, PZT) transducers. However, for broader applications of piezoelectric sensors, the PZT is a suboptimal candidate due to its unstable output at temperatures above 200 °C and potential environmental hazard. A recent research objective is to produce a more effective, safer, and eco-friendly material than PZT for piezoelectric pressure sensors by incorporating lead-free materials, such as other ceramics or polymeric composites. Among lead-free materials, gallium nitride (GaN) has a notable piezoelectric coefficient and demonstrates the greatest potential to replace the PZT as a result of its performance in high temperature and pressure operating conditions. In this study, GaN thin film is used as a sensing material, where the sensor is made by a simple layer transferring process after the removal of silicon substrate. The output potential values of GaN with respect to gas pressure levels are 42.3, 76.8, 98.7, and 122.1 mV for 50, 100, 150, and 200 psi, respectively, well matched to simulated results. Additionally, the potentials measured at elevated temperatures produce reliable outputs at high temperatures up to 350 °C. Furthermore, the stability of sensor outputs at room temperature and elevated temperatures with various pressure levels was confirmed.

压电材料在汽车和石油领域等各种工业应用中有望用于压力传感器。典型的压电传感器严重依赖锆钛酸铅（Pb [Zr _x Ti _1-x ] O ₃，PZT）传感器。但是，对于压电传感器的更广泛应用，由于PZT在200°C以上的温度下不稳定的输出以及潜在的环境危害，因此是次优的选择。最近的研究目标是通过结合无铅材料（例如其他陶瓷或聚合物复合材料），生产出比PZT更有效，更安全，更环保的压电压力传感器材料。在无铅材料中，氮化镓（GaN）具有显着的压电系数，并且由于其在高温和高压操作条件下的性能而具有替代PZT的最大潜力。在这项研究中，GaN薄膜用作传感材料，其中传感器是在去除硅衬底后通过简单的层转移工艺制成的。在50、100、150和200 psi的压力下，GaN的输出电位值相对于气压水平分别为42.3、76.8、98.7和122.1 mV，与模拟结果非常吻合。此外，在高温下测得的电势在高达350°C的高温下也能产生可靠的输出。此外，确认了传感器输出在室温和各种压力水平下的高温下的稳定性。