کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7839897 | 1505860 | 2018 | 28 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Temperature dependent Cr3+ photoluminescence in garnets of the type X3Sc2Ga3O12 (Xâ¯=â¯Lu, Y, Gd, La)
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Broad band near-infrared (NIR) light sources have great potential, e.g., in optical communication and non-invasive medical imaging. Here we report the optical properties of X3Sc2Ga3O12 (Xâ¯=â¯Lu, Y, Gd, La) garnets doped with Cr3+ showing efficient 4T2 â 4A2 broad band NIR emission between 600 and 1000â¯nm. The chromium-doped garnets were investigated in view of their capability for blue to NIR conversion in high power phosphor converted LEDs (pcLEDs). Typical high power (In,Ga)N LEDs reach junction temperatures up to 450â¯K. Hence, the photoluminescence (PL) quenching temperature is a crucial parameter for on-chip phosphors. The Cr3+-doped garnets reveal very high quenching temperatures for the broad band NIR emission, ~â¯700â¯K for Lu3Sc2Ga3O12, Y3Sc2Ga3O12, Gd3Sc2Ga3O12, and 450â¯K for La3Sc2Ga3O12. The high quenching temperatures are in line with a small Stokes shift (~â¯2400â¯cmâ1) and weak electron-phonon coupling. To gain further insight in the luminescence properties, low temperature photoluminescence measurements were done. The optical properties of Cr3+ ions in garnets were analyzed in terms of the crystal field strength, Racah parameters, and phonon coupling parameters. The suitability for application in pcLEDs for high power broad band NIR sources was confirmed by emission measurements of ceramic pellets upon blue LED excitation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 202, October 2018, Pages 523-531
Journal: Journal of Luminescence - Volume 202, October 2018, Pages 523-531
نویسندگان
Beata Malysa, Andries Meijerink, Thomas Jüstel,