PLD growth of high vapor pressure antimony sulpho-iodide ferroelectric films for IR applications

Good quality films of ferroelectric SbSI have been successfully grown by the pulsed laser deposition (PLD) method. Films with thickness ranging from 2-5 μm were reproducibly obtained by optimizing the growth parameters. The as-grown films were amorphous. But post growth annealing of films at 250°C for 5 minutes in air and cooling them at the rate of 0.7°C/minute resulted in the c-axis orientation of the majority of crystallites. X-ray diffraction analysis reveals that the prominent peaks correspond to (002) and (121) planes. SEM and AFM investigations showed that the films were particulate-free and had smooth surfaces. Slow rate of heating and cooling were necessary to obtain crack-free films. The peak dielectric constant at the Curie point of 19±1°C corresponds to 5200 for a film of 4 μm thickness. The peak value of pyroelectric current and coefficient are 0.32 μA and 0.124 μC cm^-2 K^-1, respectively. PLD technique of film growth has been applied for the first time for a high vapor pressure ferroelectric material such as SbSI. The results confirm the usefulness of this technique for the growth and integration of SbSI for IR imaging and other applications