Piezo- and pyroelectric properties of lead scandium tantalate thin films

Abstract

This paper discusses the piezo- and pyroelectric properties of lead scandium tantalate thin films prepared by modified sol-gel technology. Films were deposited on Pt/Ti/SiO₂/Si-sub-strates at 530–630 °C. The quality of the thin films was optimized by design of both the deposition conditions and the solution chemistry. These approaches include spin coating speed, drying plus crystallization temperature and time, drying atmosphere, the use of rapid thermal annealing, PST sol composition, Pb-excess concentration and mixing method. The finished thin films were characterized by optical microscopy, X-ray diffraction, atomic force microscopy, and pyroelectric measurements at 30°C under a DC-bias. Piezo-response AFM was conducted on PST to monitor various piezoelectric responses, which depend on the micro-structure of the film. The maximum pyroelectric figure-of-merit F_D was 3.85×10^?5 Pa^?1/2 at 30°C and 1 kHz under a 35 V DC-bias.