Enhanced white light emission from a Tm³⁺/Yb³⁺/Ho³⁺ co-doped Na₄ZnW₃O₁₂ nano-crystalline phosphor via Li⁺ doping

Abstract

This paper reports white light emission from a Tm3+/Yb3+/Ho3+ co-doped Na4ZnW3O12 nano-crystalline phosphor synthesized through a solution combustion method.

Concentration and pump power-mediated color tunability, optical heating and temperature sensing via TCLs of red emission in an Er3+/Yb3+/Li+ co-doped ZnGa2O4 phosphor

“…A similar result was also obtained by our group in which the particle size of the phosphor was increased in the presence of Li + ions. 6 It has also been noticed that the addition of Ca 2+ ion changes the particle shape and size of the Er 3+ doped phosphor, which are conducive for increasing the corresponding luminescence intensity of the phosphor signicantly. 64 In our case, the particle shape and size of the phosphor were changed in the presence of Li + ions, which can possibly improve the UC emission intensity of the phosphor sample.…”

“…In fact, the Yb 3+ ion absorbs NIR wavelength (i.e., 980 nm) efficiently and transfers its energy to the Er 3+ ion, which can yield larger UC emission intensity. 2,6,7 3.3.2 Optical band gap analysis. The UV-vis-NIR absorption data have been monitored in the K-M (Kubelka-Munk) mode and used to calculate the optical band gap of the phosphors.…”

“…[37][38][39][40][41] It has been observed earlier that they enhance the intensity of the materials by modifying the local crystal eld around the activator ions. 6,69 The modication in the local crystal eld is achieved when larger ionic radii ion is incorporated at the sites of smaller ionic radii ion. It is expected that the incorporation of the larger sized ion creates an expansion in the crystal lattice parameters and thereby improves the intensity of the phosphor materials.…”

“…[1][2][3][4] The rare earth ions exhibit abundant energy levels and result in interesting luminescence of narrow band widths due to the wide range of lifetimes, i.e., from few milliseconds (ms) to microseconds (ms). [5][6][7][8][9][10][11] The rare earth-doped upconversion phosphor materials are very encouraging materials and have a large number of technological applications in various elds, such as lightemitting diodes (LEDs), induced optical heating, temperature sensing, chemo-dynamic and photo-dynamic therapy, cancer treatment, bio-thermal treatment, bio-imaging, and theranostics. [12][13][14][15][16][17][18][19] Basically, upconversion is a non-linear optical process, and it is characterized by anti-Stokes emissions, in which two or more low-energy photons are added together and are converted into a high-energy photon.…”

Люминофор Ближнего И Коротковолнового Ик-Диапазона На Основе Ниобата Литий-Лантана Со Структурой Кубического Граната

“…Основываясь на расположении энергетических уровней иона гольмия и учитывая ранее полученные данные для германиевых соединений [12], следует ожидать протекание двухфотонного процесса. Таким образом, заполнение 5 F 2 , 3 K 8 уровня иона Ho 3+ может происходить двумя различными путями: кросс-релаксационным процессом, по указанной выше схеме, и, в меньшей мере, за счет поглощения возбужденным состоянием в Ho 3+ : 5 [31,36,37]. Соответственно, последующие безызлучательные переходы с уровня 5 F 2 , 3 K 8 приводят к заселению нижележащих уровней 5 F 4 , 5 S 2 и 5 F 5 , с которых происходят переходы на 5 I 7 и основное 5 I 8 состояния, сопровождающиеся слабой эмиссией при 650 и 750 nm, соответственно.…”