Unveiling the synergistic effect of A-site doping in perovskite nanosheets and electrode modulation for boosting dielectric performance of printed microcapacitors

Abstract

Inkjet printing of two-dimensional (2D) perovskite nanosheets offers a promising avenue for manufacturing high-performance microcapacitors. However, optimizing and improving the dielectric performance of these printed microcapacitors remains a significant challenge. Here, Bi-doped Sr₂Nb₃O₁₀ perovskite nanosheets are engineered, dispersed in an environmentally friendly water/ethanol mixed solvent, and meticulously assembled with Ag and graphene into microcapacitors by inkjet printing technology. Enhanced dielectric performance is achieved by controlling the Bi doping content and fine-tuning the electrode/dielectric interface. A high capacitance density of approximately 193 nF cm⁻² and an impressive dielectric constant reaching up to 250 are demonstrated in inkjet-printed graphene/Sr_1.7Bi_0.3Nb₃O₁₀/graphene microcapacitors. Such microcapacitors also feature good insulating performance with a moderate electrical breakdown strength of ∼1 MV cm⁻¹, robust flexibility, strong electric field stability within 40 V, excellent stability up to 200 °C, and moderate reproducibility of ∼76.7%. Additionally, these devices exhibit a high sensitivity to chemical solvents of different polarities, which can significantly enhance the dielectric performance of these printed microcapacitors. Our work may provide an effective route to improve the dielectric performance of inkjet-printed microcapacitors based on 2D dielectric nanosheets.