Pulsed laser deposition of layered ferroelectric samarium-substituted bismuth oxide films and their diode performance

Pulsed laser deposition (PLD) is used to grow high-quality, epitaxial thin films of lead-free ferroelectric samarium-substituted bismuth oxide (Bi_2-xSm_xO_3-δ, BSO). While recent studies have demonstrated robust ferroelectricity in BSO films grown by chemical solution methods, growth by physical vapor deposition techniques and the resulting film properties remain less explored. Here, we systematically investigate the influence of PLD growth parameters (temperature, pressure, ambient gas) on the structural and electrical properties of BSO on Nb:SrTiO₃ substrates. The optimized growth conditions yield smooth, single-crystalline films with polarization-induced non-volatile resistance switching. Ferroelectric diodes fabricated from these PLD-grown BSO films exhibit promising performance metrics, including an ON/OFF ratio >10³, stable retention >10⁴ s, and robust endurance over 1.5 × 10⁴ cycles. This work introduces PLD as a viable route for integrating BSO into all-oxide devices and provides a comparison point for understanding how the growth methodology impacts the functional properties of this emerging layered ferroelectric.