Pyroelectric thin films - Past, present, and future

Pyroelectrics are a material class that undergoes a change in polarization as the temperature of the system is varied. This effect can be utilized for applications ranging from thermal imaging and sensing to waste-heat energy conversion to thermally driven electron emission. Here, we review recent advances in the study and utilization of thin-film pyroelectrics. Leveraging advances in modeling, synthesis, and characterization has provided a pathway forward in one of the more poorly developed subfields of ferroelectricity. We introduce the complex physical phenomena of pyroelectricity, briefly explore the history of work in this space, and highlight not only new advances in the direct measurement of such effects but also how our ability to control thin-film materials is changing our understanding of this response. Finally, we discuss recent advances in thin-film pyroelectric devices and introduce a number of potentially new directions the field may follow in the coming years.Over the years, our team received support from numerous sources for the development of these techniques and scientific studies, including the Air Force Office of Scientific Research (Grant No. AF FA 9550-11-1-0073), the Army Research Office (Grant Nos. W911NF-10-1-0482 and W911NF-14-1-0104), the Office of Naval Research (Grant No. N00014-10-1-0525), the National Science Foundation (Grant Nos. DMR-1149062, DMR-1451219, and DMR-1708615), the European Union’s Horizon 2020 (Marie Skłodowska-Curie Grant No. 797123), and the U.S. Department of Energy, Office of Basic Energy Sciences [Grant Nos. DEFG02-07ER46459 and DE-AC02-05-CH11231 (Materials Project Program No. KC23MP)]