SnCN₂: A Carbodiimide with an Innovative Approach for Energy Storage Systems and Phosphors in Modern LED Technology

The carbodiimide SnCN₂ was prepared at low temperatures (400 °C–550 °C) by using a patented urea precursor route. The crystal structure of SnCN₂ was determined from single-crystal data in space group C2/c (no. 15) with a=9.1547(5), b=5.0209(3), c=6.0903(3) Å, β=117.672(3), V=247.92 ų and Z=4. As carbodiimide compounds display remarkably high thermal and chemical resistivity, SnCN₂ has been doped with Eu and Tb to test it for its application in future phosphor-converted LEDs. This doping of SnCN₂ proved that a color tuning of the carbodiimide host with different activator ions and the combination of the latter ones is possible. Additionally, as the search for novel high-performing electrode materials is essential for current battery technologies, this carbodiimide has been investigated concerning its use in lithium-ion batteries. To further elucidate its application possibilities in materials science, several characterization steps and physical measurements (XRD, in situ XANES, Sn Mössbauer spectroscopy, thermal expansion, IR spectroscopy, Mott-Schottky analysis) were carried out. The electronic structure of the n-type semiconductor SnCN₂ has been probed using X-ray absorption spectroscopy and density functional theory (DFT) computations.