BEPOLAR

Emerging communication technologies (5G, NFC) require refined Ferroelectric Film (FE) varactors to operate at higher frequencies or lower voltages. The interface 'dead layer' FE and increased leakage current limit this evolution. Recent ab initio calculations show, at the electrode/FE perovskite interfaces, the influence of chemical, polar and structural disparities on the stabilization of polarization and the Schottky barrier height (SBH). We propose a systematic interface engineering using combinatorial laser ablation deposition. Local investigation by spectroscopies and advanced microscopies of chemically modulated interfaces, combined with DFT calculations, will lead to the identification of optimized materials (minimum FE layer and increased SBH), as well as understanding the underlying physical and chemical mechanisms. The best interfaces will be tested in industrial varactors.