Boosting energy storage performance of low-temperature sputtered CaBi2Nb2O9 thin film capacitors via rapid thermal annealing

CaBi2Nb2O9 thin film capacitors were fabricated on SrRuO3-buffered Pt(111)/Ti/Si(100) substrates by adopting a two-step fabrication process. This process combines a low-temperature sputtering deposition with a rapid thermal annealing (RTA) to inhibit the grain growth, for the purposes of delaying the polarization saturation and reducing the ferroelectric hysteresis. By using this method, CaBi2Nb2O9 thin films with uniformly distributed nanograins were obtained, which display a large recyclable energy density W-rec approximate to 69 J/cm(3) and a high energy efficiency eta approximate to 82.4%. A superior fatigue-resistance (negligible energy performance degradation after 10(9) charge-discharge cycles) and a good thermal stability (from -170 to 150 degrees C) have also been achieved. This two-step method can be used to prepare other bismuth layer-structured ferroelectric film capacitors with enhanced energy storage performances.

Automated summary

The CaBi2Nb2O9 thin film capacitors fabricated using a two-step process displayed uniformly distributed nanograins, large recyclable energy density, high energy efficiency, superior fatigue-resistance, and good thermal stability. This method can be applied to prepare other bismuth layer-structured ferroelectric film capacitors with enhanced energy storage performances.