Realizing multicolor emissions of upconversion (UC) luminescence materials is of significant importance for information security and anticounterfeiting fields. Herein, a strategy is reported to achieve UC multicolor luminescence through manipulating the electronic transition process under dual‐wavelength excitation. The novel color can be produced via exploiting the synergistic effect of photons under dual‐wavelength excitation to control electron distribution, and can be further modulated by finely adjusting the excitation power. Furthermore, the range of color‐tunable emissions is expanded by adjusting Yb3+ ions concentrations due to the energy back transfer (EBT) process. Inspired by this, the materials with broad‐range UC multicolor emissions can be used to design high‐capacity photonic barcodes for anticounterfeiting applications, which provides a significant step for advanced anticounterfeiting of high level security.

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The rational development of multicolor upconversion (UC) luminescent is particularly promising for achieving high-tech anti-counterfeiting and security applications. Here, the Ho3+ and Yb3+ ions co-doped KLa(MoO4)2 material can achieve multicolor...

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Rational design of multicolor upconversion (UC) luminescent to achieve cryogenic optical thermometers holds exotic potential applications in many high-tech fields. Here, a strategy is proposed to design multicolor UC luminescence by thermally manipulating the electronic transition process, which could be used to achieve optical temperature sensing. The nonthermally coupled energy levels could control the emission intensity of the corresponding energy levels through the nonradiative relaxation process, thus allowing for achieving high sensitivity cryogenic sensing. The Er 3+doped material exhibited thermochromic luminescence properties due to the unique thermal response mechanism, which enables the creation of novel multimode temperature measurements of visual reading and digital recognition. These results not only shed new insights on the luminescence mechanism under specific excitation conditions but also offer a novel strategy for the realization of cryogenic optical thermometers.