Effects of full-range Eu concentration on Sr^sub 2-2x^Eu^sub 2x^Si^sub 5^N^sub 8^ phosphors: A deep-red emission and luminescent thermal quenching

• Published in: Journal of alloys and compounds Vol. 770; p. 1069
• Main Authors: Liu, Xiaolang, Song, Zhen, Kong, Yuwei, Wang, Shuxin, Zhang, Shiyou, Xia, Zhiguo, Liu, Quanlin
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier BV 05-01-2019
• Subjects: Emission analysis; Energy transfer; Europium; Light emitting diodes; Luminescence; Organic light emitting diodes; Phosphors; Phosphorus; Quenching; White light
• ISSN: 0925-8388; 1873-4669

To fabricate white-light-emitting diodes (white LEDs) with high color-rendering index or full light spectrum emission, the discovery of more efficient deep-red emitting phosphor materials is essential. In this paper, we have synthesized a series of Sr2-2xEu2xSi5N8 (0 ≤ x ≤ 1) solid-solution compounds, and have systemically investigated effects of full-range Eu concentration on their luminescence. Their emission band maximum can be largely tuned from 610 to 725 nm by increasing Eu content. Reabsorption at low Eu2+ concentration while both the energy transfer and Stocks shift at high Eu2+ concentration account for this large spectral red-shift. Luminescent thermal quenching performance gets worse with Eu2+ concentration increasing. The compound with x = 0.15 possesses the best crystallinity and the highest luminescence intensity with the peak position around 660 nm, and still maintains 88.5% room-temperature intensity at 400 K, indicating that great potential for the application as a deep-red phosphor.