Preparation and investigation of Dy/Tm-doped NaGd(MoO) with thermal stability and tunable white light emission for LED applications

• Published in: CrystEngComm 2022-01, Vol.24 (4), p.85-817
• Main Authors: Yu, Xiaochen, Jiang, Yinlin, Li, Xiaojie, Song, Zeyu, Zhang, Xu, Liu, Haonan, Zhao, Baoyan, Ye, Ting, Duan, Li, Fan, Jibin
• Format: Article
• ISSN: 1466-8033
• DOI: 10.1039/d1ce01434j

In this work, a series of Dy 3+ -doped, Tm 3+ -doped, and Dy 3+ /Tm 3+ co-doped NaGd(MoO 4 ) 2 (NGM) phosphors were successfully prepared via a high-temperature solid-state method. The crystal structure, band structure, elemental composition, and photoluminescence (PL) properties were investigated in detail. These crystals showed a tetragonal structure with the space group I 41/ a (88), which endowed NGM with excellent chemical and thermal stability. The positions of the diffraction peaks of the doped samples were slightly righted shift, indicating that the Dy 3+ and Tm 3+ ions occupied the position of the Gd 3+ ions. The photoluminescence results showed that bright white light emission could be achieved by adjusting the excitation wavelength or controlling the ratio of the Dy 3+ and Tm 3+ ions concentration. The obtained optimal chromaticity coordinate (0.3334, 0.3310) for the NGM: 0.06Dy 3+ , 0.12Tm 3+ phosphor was very close to the standard white light (0.333, 0.333) coordinate under near-ultraviolet (364 nm) excitation. Additionally, the temperature-dependent spectra were also investigated, which indicated that this phosphor has excellent thermal stability under 423 K. In conclusion, Dy 3+ /Tm 3+ co-doped NGM has potential for application in white LEDs. Combining theoretical calculations and experiments, synthesized NaGd(MoO 4 ) 2 : 0.06Dy 3+ z Tm 3+ phosphors are shown to have good stability. Under 364 nm excitation, the phosphors emit tunable white light and demonstrate good thermal stability.