Upconversion emission of erbium-doped lanthanum oxysulfide powders for temperature sensing

摘要

In this work we report a detailed spectroscopic study of the near-infrared to visible upconversion luminescence in Erdoped lanthanum oxysulfide crystal powders after excitation of level ~4I_(9/2). The analysis of the decay curves of the upconversion emission indicates that energy transfer upconversion is the main mechanism responsible for the green (~4S_(3/2)) and red (~4F_(9/2)) upconversion luminescence. The temperature dependence of the green upconverted emission from the two thermally coupled ~2H_(11/2) and ~4S_(3/2) levels has been analyzed in the 230 K- 300 K temperature range in order to check its availability as a temperature sensor.