Optimization of sputtering parameters of chromium nitride thin films for high temperature solar applications

This research deals with the deposition and characterization of chromium nitride (CrN) thin film developed by DC/RF magnetron sputtering, emphasizing effects of gas flow rates and power on mechanical, optical, and structural properties of the films. Chromium nitride (CrN) has been deposited on glass substrate at different mixer of argon and nitrogen gas flow rate 10:8, 20:20, and 30:10 sccm and sputtering power 150, 220, and 300 W. Optical analysis was performed using UV-VIS-NIR spectrophotometer, confirming that indeed, reflectance increased on increasing the wavelength, while maximum reflectance happened at flow rate of 10:8 sccm and 300 W. The AFM images suggested that surface roughness showed an increased with higher power and gas flow, ranging from 3.22 nm to 20.45 nm. From nanoindentation results, hardness and elastic modulus increased with power with an impressive hardness of 1.94 GPa at 30:10 sccm and 300 W. The outcome indicates that CrN thin films deposited at lower gas flow rates have better optical absorption, which can be useful for solar absorber coatings. The study contributes significantly towards optimizing sputtering parameters and improving the application of CrN thin film in high temperature solar applications.