Characterization of buried thin films with resonant soft x-ray fluorescence

The geometric and electronic structure of a buried monolayer of boron nitride (BN) has been probed using resonant soft x-ray fluorescence (SXF). By using the strong π* resonance feature in the resonant fluorescence spectrum near the B (1s) threshold, we were able to detect the BN thin film and examine changes in its electronic structure when the monolayer is placed between different materials. Our results demonstrate the capability of the resonant SXF technique for probing the element-specific electronic structure of a buried thin film nondestructively.