Piezo- and pyroelectric properties of lead scandium tantalate thin films

This paper discusses the piezo- and pyroelectric properties of lead scandiu m tantalate thin films prepared by modified sol-gel technology. Films were deposited on Pt/Ti/SiO2/Si-substrates at 530-630 degreesC. The quality of t he thin films was optimized by design of both the deposition conditions and the solution chemistry. These approaches include spin coating speed, dryin g plus crystallization temperature and time, drying atmosphere, the use of rapid thermal annealing, PST sol composition, Pb-excess concentration and m ixing method. The finished thin films were characterized by optical microsc opy, X-ray diffraction, atomic force microscopy, and pyroelectric measureme nts at 30 degreesC under a DC-bias. Piezo-response AFM was conducted on PST to monitor various piezoelectric responses, which depend on the microstruc ture of the film. The maximum pyroelectric figure-of-merit F-D was 3.85x10( -5) Pa-1/2 at 30 degreesC and 1 kHz under a 35 V DC-bias.