Details

Autor(en) / Beteiligte

• He, Shinan
• Xia, Haiping
• Zhang, Jianli
• Zhu, Yongsheng
• Chen, Baojiu

Titel

Highly efficient up-conversion luminescence in Er3+/Yb3+ co-doped Na5Lu9F32 single crystals by vertical Bridgman method

Ist Teil von

• Scientific reports, 2017-08, Vol.7 (1), p.1-9, Article 8751

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Abstract Er 3+ /Yb 3+ co-doped Na 5 Lu 9 F 32 single crystals with different concentrations of Yb 3+ ions were prepared to investigate their phase structure, up-conversion (UC) properties and mechanism of UC luminescence by Bridgman method. Under 980 nm near-infrared (NIR) excitation, three sharp UC emission bands topping at green ~525 nm, ~548 nm and red ~669 nm were obtained in Er 3+ /Yb 3+ doped Na 5 Lu 9 F 32 single crystals which are attributing to the transitions of 2 H 11/2  →  4 I 15/2 , 4 S 3/2  →  4 I 15/2 and 4 F 9/2  →  4 I 15/2 , respectively. The quadratic dependence of pump power on UC emission indicated that two-photon process is in charge of the transition from excited state of Yb 3+ ions to lower state of Er 3+ ion in Na 5 Lu 9 F 32 single crystals. The long-accepted mechanism for the production of red and green emissions through up-conversion (UC) under 980 nm excitation in Er 3+ /Yb 3+ co-doped materials apply in the Na 5 Lu 9 F 32 host was displayed. The enhancement of the red emission was observed due to a cross-relaxation (CR) process of the form: 4 F 7/2  +  4 I 11/2  →  4 F 9/2  +  4 F 9/2. Furthermore, an ideal yellowish green light performance could be achieved with 1.0 mol% Er 3+ doped certain Yb 3+ concentrations samples, and its external quantum efficiency approached to 6.80% under 5.5 Wcm −2 980 nm excitation which can be applied in developing UC displays for electro-optical devices.