Grigorjevaite Julija, Katelnikovas Arturas
Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania.
Materials (Basel). 2023 Feb 3;16(3):1305. doi: 10.3390/ma16031305.
Nowadays, scientists are interested in inorganic luminescence materials that can be excited with UV or NIR radiation and emit in the visible range. Such inorganic materials can be successfully used as luminescent or anti-counterfeiting pigments. In this work, we report the synthesis and optical properties investigation of solely Tm doped and Yb/Tm co-doped KGd(PO)(WO) phosphors. The single-phase samples were prepared using a solid-state reaction method. The Tm concentration was changed from 0.5% to 5%. Downshifting and upconversion emission studies were performed under 360 nm and 980 nm excitation, respectively. Yb ions were used as sensitizers in the KGd(PO)(WO) phosphors to transfer the captured energy to Tm ions. It turned out that under UV excitation, phosphors emitted in the blue spectral area regardless of the presence or absence of Yb. However, a very strong deep-red (~800 nm) emission was observed when Yb and Tm-containing samples were excited with a 980 nm wavelength laser. It is interesting that the highest upconversion emission in the UV/Visible range was achieved for 20% Yb, 0.5% Tm doped sample, whereas the sample co-doped with 20% Yb, 2% Tm showed the most intensive UC emission band in the NIR range. The materials were characterized using powder X-ray diffraction and scanning electron microscopy. Optical properties were studied using steady-state and kinetic downshifting and upconversion photoluminescence spectroscopy.
如今，科学家们对能够被紫外光或近红外辐射激发并在可见光范围内发光的无机发光材料感兴趣。这类无机材料可成功用作发光或防伪颜料。在本工作中，我们报道了纯Tm掺杂以及Yb/Tm共掺杂的KGd(PO)(WO)荧光粉的合成及光学性质研究。采用固相反应法制备单相样品。Tm浓度从0.5%变化到5%。分别在360 nm和980 nm激发下进行了下转换和上转换发射研究。在KGd(PO)(WO)荧光粉中，Yb离子用作敏化剂，将捕获的能量传递给Tm离子。结果表明，在紫外激发下，无论是否存在Yb，荧光粉均在蓝色光谱区域发光。然而，当含Yb和Tm的样品用980 nm波长激光激发时，观察到非常强的深红色（~800 nm）发射。有趣的是，对于20%Yb、0.5%Tm掺杂的样品，在紫外/可见光范围内实现了最高的上转换发射，而共掺杂20%Yb、2%Tm的样品在近红外范围内显示出最强的上转换发射带。使用粉末X射线衍射和扫描电子显微镜对材料进行了表征。使用稳态和动力学下转换及上转换光致发光光谱研究了光学性质。
