Silicon-Integrated Lead-Free Batio3-Based Film Capacitors With Excellent Energy Storage Performance And Highly Stable Irradiation Resistance

Silicon integrated lead-free oxide thin film capacitors with high energy storage density (W-re), high efficiency (eta) and good thermal stability have great application potential in modern communication fields. Here, 1 mol% SiO2-doped Ba(Zr0.35Ti0.65)O-3 (BZTS) thin film capacitors are integrated on Si and HfO2 buffered Si substrates by using a radio-frequency magnetron sputtering system. It is found that the energy storage performances are significantly improved by inserting an HfO2 buffer layer (about 13.5 nm) between the BZTS layer and the Si substrate. The improved W-re of the BZTS/HfO2 thin film capacitors can be up to 93.48 J cm(-3) at room temperature, which is about 65% higher than that of the film without the HfO2 buffer layer, and the eta is similar to 71.44%. Moreover, the introduction of the HfO2 buffer layer leads to a superior thermal stability in a wide temperature range from -100 degrees C to 200 degrees C with a very small change rate of similar to 3.39%. Under different irradiations with doses of He+ from 1 x 10(12) ions per cm(2) to 7 x 10(15) ions per cm(2) and neutrons from 5 x 10(12) ions per cm(2) to 1 x 10(14) ions per cm(2), the BZTS thin film capacitors with the HfO2 buffer layer show ultra-stable energy storage performance. Our research provides an effective strategy for the integration of high performance BZTS thin film capacitors on Si substrates, and our results demonstrate potential of the Si integrated thin film capacitors for the application in nuclear technology, space stations, satellites, radiation centers and other harsh environments.