Hydrothermal Synthesis of Zn₂GeO₄ and Mn²⁺ Doped Zn₂GeO₄ (ZGO) Nanoparticles with Controlled Luminescent Properties

Abstract

This paper reports the first attempt to synthesize un-doped spherical Zn 2 GeO 4 stoichiometry and Mn 2+ doped Zn 2 GeO 4 nanoparticles to achieve a controlled luminescence, particularly, by changing Zn:Ge ratio and Mn 2+ concentration during the hydrothermal process. The morphology of the un-doped Zn 2 GeO 4 nanoparticle was depended on the Zn:Ge ratio that was observed to have a nanorod structure to spherelike morphology; however, the morphology of Mn 2+ doped Zn 2 GeO 4 was not changed as the use of Mn 2+ as a dopant. The un-doped Zn 2 GeO 4 showed a broad emission at ³510 nm and its intensities were functioned of Zn:Ge ratio. On the other hand, the Mn 2+ doped Zn 2 GeO 4 showed emission peaks at ³532 nm and they can be attributed to the 4 T 1 ¼ 6 A 1 transition in Mn 2+ ions doped in Zn 2 GeO 4 . These results suggest the effectiveness use of Zn:Ge ratio and Mn 2+ doped Zn 2 GeO 4 in tuning the luminescence of Zn 2 GeO 4 nanoparticles, which are of potential applications as phosphors in wide range of engineered fields, in particular optoelectronics.

Dynamic Luminescence of Lead-Doped Calcium Zinc Germanate Clinopyroxene for Multimode Anticounterfeiting

“…Numerous studies have focused on utilizing germanate as a host material that contains various dopants to create phosphor materials with exceptional luminescent properties. For example, germanate material Zn 2 GeO 4 (ZGO) has been intensively studied in the last few decades, − and ZGO-based phosphor materials have been utilized in anticounterfeiting labels with excellent outcomes. − Other germanate materials could also be good candidates for anticounterfeiting applications. One such material is CaZnGe 2 O 6 [calcium zinc germanate (CZGO)], which is a clinopyroxene material utilized in long persistent luminescence phosphors. − The dopants used in CZGO clinopyroxene include chromium (Cr); , manganese (Mn); , bismuth (Bi); , dysprosium (Dy); terbium (Tb), and lead (Pb) .…”