Ultra-wideband phosphor Mg2Gd8(SiO4)6O2:Ce3+,Mn2+: Energy transfer and pressure-driven color tuning for potential applications in LEDs and pressure sensors

Energy transfer and pressure-driven color tuning phosphor Mg2Gd8(SiO4)6O2:Ce3+ (MGS:Ce3+), with ultra-wideband spectra was synthesized by high-temperature solid-state method. When the phosphor was excited by ultraviolet light, it emitted a sort of cold near-white light. The photoluminescence emission (PL) and excitation (PLE) spectra, luminescence sites of MGS:Ce3+ had been researched. In order to adjust the light color to achieve the purpose of spectral tuning, two methods had been implemented. The first method was doping Mn2+ into MGS:Ce3+. There was energy transfer from Ce3+ to Mn2+ in such phosphor, and the energy transfer had been researched in detail. After doping with Mn2+, the color coordinates positions and correlated color temperature (CCT) of phosphors were improved obviously. When fixed the concentration of Ce3+ and the doping concentration of Mn2+ is y = 1.0, 2.0 and 3.0, the phosphor can realize the warm white light emission. The second one was applying pressure to MGS:Ce3+, expecting to achieve the above purpose through the red shift of the spectrum. The results showed that the sample could withstand the high pressure of 26.03 GPa. A relatively rare phenomenon of pressure enhancement emission appeared when the pressure was between atmospheric pressure and 3.17 GPa. When the pressure exceeded 3.17 GPa, the luminescence intensity decreased regularly with the increase of pressure and the phosphor showed high pressure sensitivity (dλ / dP ≈ 1.8453 nm GPa−1). What’s more, the sample at compression environment made a significant red-shift about 60 nm of the emission bands. In the process of compression, the color coordinate shows that the light color of phosphor can be adjusted from blue-green light to yellow light region under the excitation of 355 nm. All above results revealed that the convenient synthetic method, effective light color coordinating made the MGS:Ce3+ and MGS:Ce3+,Mn2+ become a potential phosphor for (warm) white light. What’s more, the emission spectra red shift resulting from pressure change made it possible to be a potential optical pressure sensor.