Organically tuned white-light emission from two zero-dimensional Cd-based hybrids

In this work, we report two zero-dimensional Cd-based hybrid compounds, denoted CdACP and CdODA, where the Cd atoms adopt tetrahedral geometry. The optical analysis reveals that these materials are classified as wide-gap semi-conductors which makes them suitable for optoelectronic applications. The photoluminescence analysis proves the wavelength dependent white-light emission behavior of the investigated materials. The structural-optical property studies show that, thanks to the heavy halide effect, the CdACP exhibits both fluorescence and room temperature phosphorescence through harvesting triplet states. Meanwhile, in contrast to CdACP, the white light emission from CdODA is purely fluorescence in nature. In fact, within CdODA, both C-H⋯π and N-H⋯N interactions facilitate the intramolecular proton transfer (ESIPT) between the different cations which leads to ultra-fast fluorescence through excited state ESIPT. Under sub-gap excitations, the inorganic sub-lattice is responsible for the blue-green emission through the STE mechanism, while the organic cations contribute by an intense red emission.