By: William Huang - Central Bucks High School South
You’ve probably used piezoelectricity several times in your life, and will continue to use it without even knowing it. It can be seen in many places, from quartz watches to microphones in your computer to ultrasound transducers, but what is this seemingly complicated, hard-to-pronounce concept? Piezoelectricity (or the Piezoelectric Effect) is a property of certain crystals that allows them to develop an electric charge when a mechanical stress is applied. Conversely, the reverse piezoelectric effect occurs when particular crystals are exposed to an electric field and are physically deformed. One of the most popular piezoelectric materials is Lead Zirconate Titanate (PZT, Pb[ZrxTi1-x]O3) thin films due to their good piezoelectric properties, easy fabrication process, and high operating temperatures. Devices that utilize PZT include infrared detectors, inkjet printer heads, and accelerometers. However, one of the main challenges in creating these thin films is that cracks often form during the fabrication process, hurting their piezoelectric properties. Because of this, my project was focused on developing improved PZT thin film recipes by varying the thickness and heating process so that the resulting films would have as little cracks as possible. I found that in general, multi-layered thin films contained less cracks but were rougher in texture than single-layered thin films. The roughness thus decreased the film’s piezoelectricity. I also found that raising temperatures gradually was optimal to reduce deformities and develop a thin film with improved characteristics and piezoelectric efficiency that has the potential to expand the real-world applications of PZT thin films.
PZT thin film research poster
This research was conducted as a part of the Partners in Science Research Program. To read more, click here for a full pdf of William's formal research paper about his project!