IL-modified perovskite films were studied using X-ray Photoelectron Spectroscopy (XPS), Near Edge X-ray Absorption Fine Structure (NEXAFS), Hard X-ray Photoelectron Spectroscopy (HAXPES), Near-Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) at ASTRID2 synchrotron and Henry Royce Facilities.