Upconversion Dynamics in Er 3+ -Doped Gd 2 O 2 S: Infl uence of Excitation Po…

Upconversion (UC) enables the conversion of lower energy to higher energy photons and has gained interest for the application in solar cells and nanocrystal biolabels. Er 3+ -doped Gd 2 O 2 S is a highly promising UC material for applications. A record UC quantum yield of 12% was recently measured in Gd 2 O 2 S doped with 10% Er 3+ upon monochromatic excitation into the 4 I 13/2 state at 1510 …