Luminescence Properties of Nd~(3+)doped LiNbO_3 LiTaO_3 sol-gel powders

摘要

This paper reports the synthesis and a detailed analysis of the luminescence properties of Nd~(3+)doped (1, 2 & 3mol %) LiNbO_3 & LiTaO_3 powders prepared by sol-gel process. The two ferroelectric hosts are potential candidates for various electronic and photonics applications. Near infrared emission transitions (~4F_(3/2)→~4I_(9/2, 11/2 & 13/2)) of Nd~(3+) at 890nm, 1060nm and 1340nm have been measured under the excitation of an Ar~+ laser (514nm & 488nm) and it has been found that the 2mol% Nd~(3+) has an intense emission compared with the other contents. An Up-conversion violet color (399nm) emission (~4D_(3/2)→4I_(13/2) (or) ~2P_(3/2) → ~4I_(11/2)) has also been observed with a 583nm excitation, which is a hypersensitive transition (~4I_(9/2) → ~4G_(5/2)) of Nd~(3+) having a strong absorption at the yellow wavelength. Apart from a bright violet up-conversion emission, three other emissions at 342nm (~4D_(3/2)→4I_(9/2)), 373nm (~2P_(3/2)→4I_(11/2) or ~4D_(3/2)→~4I_(13/2)) and 464nm (~2P_(3/2)→~4I_(13/2)) have also been measured. The violet up-conversion emissions have been explained using an energy level diagram. The structural details and particle sizes of Nd~(3+) doped LiNbO_3 & LiTaO_3 powders have been studied from the patterns of XRD and SEM images.