Upconversion Luminescence through Cooperative and Energy‐Transfer Mechanisms in Yb³⁺‐Metal‐Organic Frameworks.

Lanthanide‐doped metal–organic frameworks (Ln‐MOFs) have versatile luminescence properties, however it is challenging to achieve lanthanide‐based upconversion luminescence in these materials. Here, 1,3,5‐benzenetricarboxylic acid (BTC) and trivalent Yb3+ ions were used to generate crystalline Yb‐BTC MOF 1D‐microrods with upconversion luminescence under near infrared excitation via cooperative luminescence. Subsequently, the Yb‐BTC MOFs were doped with a variety of different lanthanides to evaluate the potential for Yb3+‐based upconversion and energy transfer. Yb‐BTC MOFs doped with Er3+, Ho3+, Tb3+, and Eu3+ ions exhibit both the cooperative luminescence from Yb3+ and the characteristic emission bands of these ions under 980 nm irradiation. In contrast, only the 497 nm upconversion emission band from Yb3+ is observed in the MOFs doped with Tm3+, Pr3+, Sm3+, and Dy3+. The effects of different dopants on the efficiency of cooperative luminescence were established and will provide guidance for the exploitation of Ln‐MOFs exhibiting upconversion. [ABSTRACT FROM AUTHOR]