Temperature Sensing Assists the Understanding of Er~(3+) Concentration Dependent Anti-Stokes Luminescence in NaYF_4:Er~(3+)/Yb~(3+) Nanophosphors

摘要

In this paper, upconverison luminescence in Er~(3+)/Yb~(3+) co-doped NaYF_4 nanophosphors was regulated by changing the Er~(3+) concentration. With increasing the Er~(3+) concentration, the green and red emissions increased first and then decreased, but the intensity ratio of red to green emission decreased monotonically. To clarify the role of Er~(3+) doping, the factors including crystal structure, morphology and size of particle, photon absorption, energy transfer, multi-phonon relaxation, population of emissive levels and emission probability of radiative transitions were considered and analyzed. More importantly, we proposed a simple method for discussing radiation transitions based on luminescence temperature sensing.