Near-Infrared Laser-Triggered Full-Color Tuning Photon Upconversion and Intense White Emission in Single Gd2O3 Microparticle

摘要

Full-color emission fluorescence materials are of imperious demand in information storage, graphics imaging, and anticounterfeiting fields. However, it is still a formidable challenge to develop a single material with full-color emission and high-purity white output under NIR-light excitation. Herein, we design a novel and convenient strategy to tune the upconversion luminescence color with full-color range in lanthanide ions-doped Gd2O3 microspheres via a single NIR laser sensitization. Different from the typical ion-dependent tuning of color, the bright and flexible full-color emission tuning from blue to cyan, green, yellow, pink, and red can be a controllable implementation in a single microparticle. Particularly, benefiting from the laser-sensitive color adjustment, highly intense white color emission can be simultaneously achieved in diverse doped ion concentration particles. In addition, the upconversion emission intensity has been evidently improved if using a NIR laser sensitization, leading to a significantly enhanced upconversion red luminescence signal (44-fold) at the power of 446 mW. The mechanistic investigations and dynamics analysis reveal that the unprecedented color tunability from these microcrystals is attributed to dynamic control of multienergy transfer and the multicross relaxation process. Furthermore, because of their excellent upconversion luminescence properties, Gd2O3 microparticles could be used in the anticounterfeiting application in different colors. These findings not only open a way to fabricate a single material for fine-tuning upconversion emission in a full-color gamut, but also give the possibility for construction of multicolor imaging for anticounterfeiting applications.