The development of lanthanide-doped Y₃Al₅O₁₂ (Ln:YAG) garnet nanostructures is a hot topic in the field of inorganic nanophosphors due to the current interest in developing small nanoparticles for solid-state lighting (SSL), displays, lasers and scintillation applications. In this study, we report the preparation of homogeneous Ln:YAG (Ln: Ho/Yb ions) nanospheres through a combined two-steps coprecipitation-solvothermal synthesis at low temperature. The crystal growth takes place in ethylene glycol, which is an inexpensive, non-toxic and easily available solvent. Monodisperse and crystalline spherical YAG particles of 80 nm in diameter were obtained. Furthermore, the protocol can be extended to other compositions (Tb/Yb, Tm/Yb…) to explore different luminescent properties, without affecting the morphology of the material, indicating the robustness and practical utility of the reported methodology. Thermal treatment of the nanogarnets at 1200°C is necessary for making materials optically active upon both UV and NIR excitation. The spherical morphology of annealed samples is preserved, what helps their further dispersion in solvents, barbotines, inks or printing vehicles. The lanthanide-doped nanogarnets exhibited the characteristic blue, green and red emissions from lanthanide upconversion photoluminescence (UCPL) upon NIR excitation. The UCPL mechanism was studied and CIE chromate coordinates were obtained. These nanogarnets were further evaluated as functional ceramic phosphors by incorporating them into commercial glazes. The materials exhibited an exceptional chemical stability in a harsh medium such as a fused glaze. Consequently, the visible emissions of the nanoparticles were transferred to the whole glass matrix, thus providing a functional glaze that emits intense blue and green light upon NIR excitation. These luminescent nanogarnets have promising applications in smart enamels, but can also be useful for lighting displays (white LEDs…), smart paintings or plastics, and anti-counterfeiting systems.

镧系元素掺杂Y ₃ Al ₅ O _12的研究进展（Ln：YAG）石榴石纳米结构是无机纳米荧光粉领域的热门话题，这是由于目前对开发用于固态照明（SSL），显示器，激光和闪烁应用的小型纳米颗粒的兴趣。在这项研究中，我们报告了通过低温下两步共沉淀-溶剂热合成的方法制备均匀的Ln：YAG（Ln：Ho / Yb离子）纳米球。晶体生长在乙二醇中，乙二醇是一种廉价，无毒且易于获得的溶剂。获得了直径为80nm的单分散和结晶球形YAG颗粒。此外，该协议可以扩展到其他成分（Tb / Yb，Tm / Yb…），以探索不同的发光特性，而不会影响材料的形态，表明所报告方法的稳健性和实用性。纳米石榴石在1200°C的热处理对于使材料在UV和NIR激发下都具有光学活性是必要的。退火样品的球形形态得以保留，这有助于将其进一步分散在溶剂，barbotines，油墨或印刷介质中。掺杂镧系元素的石榴石在NIR激发下表现出来自镧系上转换光致发光（UCPL）的特征性蓝色，绿色和红色发射。研究了UCPL机理，获得了CIE铬酸盐坐标。通过将它们掺入市售釉料中，进一步评价了这些纳米石榴石是否为功能陶瓷荧光粉。该材料在苛刻的介质（如熔融釉）中表现出出色的化学稳定性。所以，纳米粒子的可见发射光被转移到整个玻璃基体上，从而提供了一种功能性釉料，在近红外激发下会发出强烈的蓝色和绿色光。这些发光的纳米石榴石在智能搪瓷中具有广阔的应用前景，但也可用于照明显示器（白光LED…），智能绘画或塑料以及防伪系统。