Spectral performance and intensive green upconversion luminescence in Er3+/Yb3+-codoped NaY(WO4)2 crystal
Autor: | Feng Song, Jing Su, Jia Yang, Huanchu Chen, Hao Tan, Jianguo Tian, Guangyin Zhang, Lin Han, Zhenxiang Cheng |
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Rok vydání: | 2006 |
Předmět: |
Materials science
Absorption spectroscopy business.industry Crystal growth Atomic and Molecular Physics and Optics Photon upconversion Electronic Optical and Magnetic Materials Crystal Optics Excited state Spontaneous emission Emission spectrum Electrical and Electronic Engineering Physical and Theoretical Chemistry Luminescence business |
Zdroj: | Optics Communications. 259:179-186 |
ISSN: | 0030-4018 |
Popis: | Using Czochralski (CZ) pulling method, an Er 3+ /Yb 3+ -codoped NaY(WO 4 ) 2 crystal was prepared. Absorption spectra, emission spectra and excitation spectra of this crystal were measured at room temperature. Some optical parameters, such as intensity parameters, spontaneous emission probabilities and lifetimes, were calculated from absorption spectra with Judd–Ofelt (J–O) theory. Upconversion luminescence excited by a 970 nm diode laser was studied. In this crystal, green upconversion luminescence is particularly intensive. Energy transfer mechanisms that play an important role in upconversion processes were analyzed. Two cross-relaxation processes: 4 G 11/2 + 4 I 9/2 → 2 H 11/2 (or 4 S 3/2 ) + 2 H 11/2 (or 4 S 3/2 ), and 4 G 11/2 + 4 I 15/2 → 2 H 11/2 (or 4 S 3/2 ) + 2 I 13/2 , which contribute to the intensive green luminescence under 378 nm excitation, were put forward. Background energy transfer 4 G 11/2 (Er 3+ ) + 2 F 7/2 (Yb 3+ ) → 4 F 9/2 (Er 3+ ) + 2 F 5/2 (Yb 3+ ) was also demonstrated. |
Databáze: | OpenAIRE |
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