Cover Feature: A Double‐Band Emitter with Ultranarrow‐Band Blue and Narrow‐Band Green Luminescence (Chem. Eur. J. 10/2020)

Eu2+-doped UCr4C4-type alkali lithosilicates exhibit green towards cyan and blue luminescence, depending on the exact composition. One possibility is that there are only sodium ions in the light-alkali-metal channel, leading the way left towards blue luminescence. However, pure lithium channels result in a green luminescence, pointing to the right turnoff. If mixed channels exist, it is the middle ground: presumably domain formation occurs, leading to a cyan double-band emission. More information can be found in the Full Paper by H. Huppertz et al. on page 2204.