Near-Infrared Luminescence from Y<SUB>2</SUB>O<SUB>3</SUB>:Eu<SUP>3+</SUP>, Yb<SUP>3+</SUP> Prepared by Sol–Gel Method

Abstract

Eu3+ and Yb3+ codoped Y2O3 phosphors were synthesized by the sol-gel method. The phosphors possess absorption in the region of 300-550 nm, exhibiting an intense NIR emission of Yb3+ around 1000 nm, which is suitable for matching the maximum spectral response of c-Si solar cells. The optimum composition of Eu3+ and Yb3+ codoped Y2O3 was (Y1.94Yb0.04Eu0.02)2O3. It is observed that two-step energy transfer occurs from the 5D2 level of Eu3+ situated around (466 nm) exciting two neighboring Yb3+ ions to the 2F5/2 level (1000 nm). The down-conversion material based on Eu(3+)- Yb3+ couple may have great potential applications in c-Si solar cells to enhance their photovoltaic conversion efficiency via spectral modification.

Yolk–shell structured Gd2O3:Eu3+ phosphor prepared by spray pyrolysis: the effect of preparation conditions on microstructure and luminescence properties

“…[22][23][24] Basically, luminescence properties of phosphors depend on the type of activators and host composition; a homogeneous distribution of activator ions throughout the host material is needed to obtain high luminescence for advanced display devices. 25 To prepare phosphor powders satisfying the requirements listed above, a number of synthetic approaches such as sol-gel, [26][27][28] combustion, 29,30 polymer precursor, 31 glycothermal, 32 spray pyrolysis, [33][34][35][36] spray drying, 37,38 and hydrothermal methods 39,40 have been investigated. As a result, the powders produced have a wide variety of morphologies, including filled sphere, hollow sphere, nanorod, nanowire, nanoplate, core-shell, tube, and fiber structures.…”

Large-scale production of spherical Y2O3:Eu3+ phosphor powders with narrow size distribution using a two-step spray drying method

“…Alternatively, repetitive ball milling and washing are required to prepare fine phosphor powders with good luminescence characteristics. 14,18,[20][21][22] To overcome these drawbacks, a variety of liquid-or gas-phase reaction methods have so far been proposed, including co-precipitation [23][24][25][26][27] , sol-gel [28][29][30][31][32][33][34] , solvothermal [35][36][37][38][39] , combustion [40][41][42][43][44][45][46][47] , spray pyrolysis [48][49][50][51][52][53] , and spray drying [54][55][56] . For industrial applications, the synthesis method should be scalable in terms of the quantity of phosphor powder required.…”