Red-emitting CaSc2O4:Eu3+ phosphor for NUV-based warm white LEDs: structural elucidation and Hirshfeld surface analysis

摘要

We have prepared Eu3+ activated phosphor from the host CaSc2O4 (CSO) via high-temperature facial solid-state route and characterized by various spectral techniques. Surface morphology and composition was determined via scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDAX). The crystal structure refinements show the Pnam 62 space group with two active centres for Eu3+ in the prepared CSO:Eu3+ phosphor. Additionally, first time the detailed investigation of intermolecular interactions through Hirshfeld surface (HSs) analysis for the inorganic phosphor has been reported, the analysis indicates that the Sc/Eu-O and Ca-O contacts in the CSO:Eu(3+)crystal account for more than 60% and 26% of the total HSs area. The synthesized phosphor shows an intense red emission at 618 nm (Ex 394 nm) with a CIE coordinates of (0.633, 0.358) and measured internal quantum efficiency (IQE) was found to be 84%. Further, correlated colour temperature was estimated to be about 6049 K including colour purity of 93.04% for Eu = 0.10 and the thermal stability were established by their temperature dependent study (400 K = 92%). Therefore, the phosphor of CSO:Eu3+ exhibits a potential application for UV-based warm white LEDs and in the determination of intermolecular interactions through HSs surface analysis studies.