Excitation-dependent energy transfer and color tunability in Dy3+/Eu3+ co-doped multi-component borophosphate glasses |
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Authors: | R. Ramaraghavulu K. Pavani P. C. Nagajyothi Jaesool Shim |
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Affiliation: | 1. Department of Physics, School of Applied Sciences, REVA University, Bangalore, Karnataka, India;2. I3N - Department of Physics, University of Aveiro, Aveiro, Portugal;3. School of Mechanical Engineering, Yeungnam University, Gyeongsan, Republic of Korea |
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Abstract: | Using the melt-quench technique, potassium zinc borophosphate (KZnBP) glasses incorporated with Dy3+, Eu3+, and Dy3+/Eu3+ ions individually and combinedly were prepared, and their photoluminescence (PL)-related features were investigated. The KZnBP glass containing an optimized content of Dy3+ (0.5 mol%) is co-doped with Eu3+ in various contents, and the energy transfer (ET) process between them was studied at λexci = 349, 364, 387 (Dy3+), and 394 nm (Eu3+). The Dy3+/Eu3+ co-doped system, when excited with Dy3+ excitations has resulted in a significant decrease in the intensity of Dy3+ peaks observed at 480 nm (4F9/2→6H15/2, blue) and 574 nm (4F9/2→6H13/2, yellow), with simultaneous enhancement of the intensity of Eu3+ peaks at 591 nm (5D0→7F1, orange) and 617 nm (5D0→7F2, red). This trend is due to the efficient energy transfer from Dy3+ to Eu3+, indicating that Eu3+ ions were sensitized by Dy3+ ions. Dexter's theory and the Inokuti–Hirayama (I–H) model revealed that the dipole–dipole interaction is accountable for the energy transfer from Dy3+ to Eu3+ through energy-transfer channels [4F9/2(Dy3+)+7F1,2(Eu3+)→6H15/2(Dy3+)+5D2(Eu3+)] and [4F9/2(Dy3+)+7F0(Eu3+)→6H13/2(Dy3+)+5D0(Eu3+)]. The color coordinates of the Dy3+/Eu3+ co-doped glasses under various excitations fall within the white light emission spectrum, indicating their potential application in warm white LEDs. |
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Keywords: | Dy3+/Eu3+ co-doped glass energy transfer photoluminescence white LEDs |
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