Improvement of the luminescent thermal stability and water resistance of K2SiF6:Mn4+ by surface passivation. Issue 12 (15th June 2022)

• Record Type: Journal Article
• Authors: Qiang, Jiawei; Wang, Lin; Wang, Tianman; Yu, Yan; Deng, Daishu; Wu, Chunxiang; Liao, Sen; Li, Shixiong
• Is Part Of: Ceramics international. Volume 48:Issue 12(2022)
• Page Start: 17253
• Page End: 17260
• Publication Date: 2022-06-15
• Subjects: Surface passivation -- Luminescent thermal stability -- Red-emitting phosphors -- Negative thermal quenching -- Water resistance; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.02.285
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Mn 4+ -doped fluoride phosphors can solve the problem for lack of red emitting component in commercial white light-emitting diodes (WLEDs). However, its application is seriously hindered by its easy hydrolysis. Here, we propose to use sodium sulfite as a passivator to treat K2 SiF6 :Mn 4+ . After passivation, a Mn 4+ -rare K2 SiF6 protective layer can be formed in situ on the surface of the phosphor, and lead to improved emission intensity, luminescent thermal stability and moisture resistance. When soaking in water for 6 h, the integrated fluorescent intensity of the passivated sample maintained 90.8% of the initial value, while the intensity of the un-passivated sample sharply decreased to 10.2% of the initial value. Mechanisms to improve the emission, water resistance and thermal stability of the luminescence are proposed and discussed. WLED was assembled with the passivated sample, and good performance of warm white light ( CCT = 2963 K, Ra = 90.4) was obtained.