Color‐Tunable Luminescence of Y4Si2N2O7:Ce3+, Tb3+, Dy3+ Phosphors Prepared by the Soft‐Chemical Ammonolysis Method

Abstract

AbstractCe3+‐, Tb3+‐, and Dy3+‐activated Y4Si2N2O7 phosphors have been prepared by the Pechini‐type sol–gel method followed by ammonolysis of the precursors. The phase purity, morphology, crystallization condition, chemical composition, and thermal stability of the products have been studied carefully by X‐ray diffraction (XRD), energy‐dispersive X‐ray (EDX), scanning electron microscopy (SEM), high‐resolution transmission electron microscopy (HRTEM), fourier‐transform infrared (FTIR), and thermogravimetry analysis (TGA) techniques. The photoluminescence (PL) and cathodoluminescence (CL) properties of Ce3+‐, Tb3+‐, and Dy3+‐doped Y4Si2N2O7 phosphors were also investigated. The electronic structure of Y4Si2N2O7 has been investigated by density‐functional theory methods. The calculations revealed that the nitrogen atom contributes more excited electrons than the O atom. The band gap has been calculated through the reflection spectrum of the Y4Si2N2O7 host. For Ce3+/Tb3+/Dy3+ singly doped Y4Si2N2O7 products, the phosphors give the typical emissions of the activators. The energy transfers from Ce3+ to Tb3+ and Dy3+ ions have been found and demonstrated through the PL spectra and luminescence decay times. The emission color of Y4Si2N2O7:Ce3+, Tb3+ and Y4Si2N2O7:Ce3+, Dy3+ samples can be tuned by energy transfer processes. Additionally, the temperature‐dependent PL properties and the degradation property of CL under continuous electron bombardment of the as‐synthesized phosphors prove that the Y4Si2N2O7 host has good stability. Therefore, the Y4Si2N2O7:Ce3+, Tb3+, Dy3+ phosphors could serve as a promising candidate for UV W‐LEDs and FEDs.