Improving the luminescence properties of the near-infrared phosphor Ca0.8Sr0.2O:Eu2+ via energy transfer and its application in the concentration detection of ethanol solutions.

In this work, a near-infrared (NIR) phosphor Ca0.8Sr0.2O:Eu2+ was prepared via a solid-state method, and its luminescence properties were improved by co-doping with Ce3+ ions. The decay curves of Ca0.8Sr0.2O:Ce3+, Eu2+ confirmed that there was an obvious energy transfer from Ce3+ to Eu2+, which enhanced the quantum efficiency of Ca0.8Sr0.2O:Eu2+. The thermal stability can also be enhanced by introducing Ce, which reduces the probability of non-radiative transitions at elevated temperatures, thereby minimizing electron loss. An NIR light emitting diode (LED) was fabricated by combining a blue LED chip with Ca0.8Sr0.2O:Ce3+, Eu2+, which was applied for the concentration detection of ethanol solutions.