Titanium molybdenum nitride/titanium nitride laminated films prepared by a high-throughput method for on-chip microsupercapacitors

Abstract

On-chip micro-supercapacitors (MSCs) have great potential in applications like wireless sensor networks and portable electronic devices. Although a lot of researches have been done to show that transition metal nitride films, such as TiN, exhibit attractive performance, make good electrodes, their power and energy densities are still insufficient. This research reports the compositional optimization of Ti_xMo_yN_z electrode films by magnetron co-sputtering on Si substrates utilizing a high-throughput technique, and the study of their electrochemical characteristics. This method can prepare multi-composition films in a single processing step, significantly reducing the time and costs compared with the traditional investigation method used for optimizing binary transition metal nitrides. At a power density of 15.8 W cm⁻³, the MSCs prepared using optimized Ti_xMo_yN_z electrode on in-situ grown TiN current collector can sustain an energy density of 30.3 mWh cm⁻³ and maintain a 93% capacitance retention rate after 10,000 charge-discharge cycles.