The electronic structure and photoluminescence properties of Ca2GeO4:Eu3+ in ultraviolet and vacuum ultraviolet region

Ca2GeO4:Eu3+ phosphors were synthesized by the solid state method. The ultraviolet and vacuum ultraviolet excited photoluminescence properties were investigated in detail. It revealed that the emission of Ca2GeO4:Eu3+ comprised two parts: the red emission of Eu3+ and host defect emission in 330-550 nm. Ca2GeO4:Eu3+ presented intense excitation intensity at 163-200 and 466 nm, which suggested the potential applications in plasma display panels and light emitting diodes. The excitation spectra were studied to identify the photoluminescence mechanisms of Ca2GeO4:Eu3+. First principles calculation within the local density approximation of the density functional theory was applied to calculate the electronic structure and linear optical properties of Ca2GeO4. - Research highlights: → Emission of Ca2GeO4:Eu3+ comprised of emissions of Eu3+ and host emission. → Ca2GeO4:Eu3+ exhibited different colors such as red, pink, blue and purple. → Excitation intensity of Ca2GeO4:Eu3+ at 466 nm was 1.7 times of that at 301 nm. → Ca2GeO4:Eu3+ is a potential candidate applied in LEDs, PDPs or free-Hg lamps.