Enhanced Supercapacitance Performance of CrO x N y Thin Films Electrodes Grown by RF Magnetron Sputtering

ABSTRACT This study presents an in‐depth analysis of the synthesis and characterization of chromium oxynitride CrO x N y films fabricated on silicon and fused silica substrates by radiofrequency magnetron sputtering, highlighting their potential application as electrodes in supercapacitors. By systematically varying the nitrogen flow rates during deposition, we achieved a tunable modification of the films' structural, electronic, and optical properties, including a significant range in bandgap energies from 1.51 to 2.85 eV. The thin films show exceptional electrochemical performance, showcasing a highly impressive areal capacitance of 75 mF/cm 2 and remarkable stability after 5000 cycles retaining 98.2% of the capacitance charge, and maintaining coulombic efficiency of 97.5% in 1 M H 2 SO 4 electrolyte. These results show the impact of growth conditions on characteristics of the films and their implications for enhancing supercapacitor performance. The combination of detailed structural, electronic, and electrochemical analyses establishes CrO x N y thin films as a versatile and promising candidate for advanced energy storage applications, offering insights into the design of supercapacitive devices with improved efficiency and durability.