Effect of Zn2+ Ions on Upconversion Emission of Er3+ in Zn/Er:LiNbO3 Crystal

摘要

The effect of Zn2+ ions codoped on the upconversion emission of Er3+ ions in Er:LiNbO3 crystal under different excitation wavelength was reported.The upconversion emission spectra of Zn/Er:LiNbO3 following 800 nm excitation reveal an enhanced green emission and a suppressed red emission simultaneously.The cross relaxationprocesses(2H11/2+4I13/2→4I11/2+4F9/2 and 4F7/2+4I11/2→4F9/2+4F9/2)are responsible for populating the red 4F9/2 emitting state.The dissociation effect of Zn2+ ions on the Er3+ cluster sites makes these cross relaxation processes inefficient.Under 980 nm excitation,the Zn2+ codoped leads to the decreased intensities of green and red upconversion emissions.These reductions are attributed to the inefficient cross relaxation processes(4I11/2+4I11/2→4F7/2+4I15/2 and 4F7/2+4I11/2→4Fg/2+4F9/2)caused by the same dissociation effect of Zn2+ ions.