K2ZnP2O7 as a next-generation self-activated phosphor: Synthesis, photoluminescence, and DFT-guided optical design

In this study, we propose a novel self-activated phosphor, K2ZnP2O7, known for its potential use as a laser host. The phosphor was successfully synthesized via the solid-state reaction method and characterized using x-ray powder diffraction (XRD), which confirmed its crystal structure. Photoluminescence studies demonstrated that K2ZnP2O7 emits blue-sky light when excited at 280 nm. Comprehensive photoluminescence measurements, including excitation and emission spectra as well as lifetime analysis, were conducted at room temperature. The chromaticity coordinates and Commission Internationale de l'Éclairage (CIE) diagram indicate that the K2ZnP2O7 phosphor falls within the blue-sky white region. Additionally, first-principles calculations based on DFT + U were performed to gain deeper insight into its electronic structure. Theoretical calculations reveal that K2ZnP2O7 possesses a direct wide band gap and minimal energy dispersion, contributing to its strong luminescence intensity. The analysis of the density of states (DOS) and absorption spectra clearly explains the origin of the experimentally observed absorption peaks. These findings highlight K2ZnP2O7 as a promising candidate for applications in UV-based light sources.