An NIR-luminescent nitrate-bridged hybrid bimetal dielectric with a switchable dielectric constant

Abstract

Hybrid perovskites are highly desirable for potential applicationsin optoelectronics. Although luminescent hybrid perovskites have a variety of technically important applications, achieving dielectric transition and near-infrared (NIR) luminescence properties simultaneously is still challenging. Herein, utilizing the NIR-luminescent properties of rare-earth ions, an Nd³⁺-containing nitrate-bridged hybrid bimetal dielectric, (MQ)₅[K₂Nd₂(NO₃)₁₃] (1; MQ = N-methylquinuclidinium cation), was successfully constructed. It exhibited a switchable dielectric constant (ε′) between low- and high-dielectric states along with NIR-luminescent property. The contrast was strikingly reached 1.88, and the was 1.18 times higher than that of silicon nitride. Furthermore, the reversibility of the switchable dielectric constant between the and at 1 MHz was observed after many ε′-switching cycles with no obvious weakening, which endowed this material with the desirable thermodynamic stability. Notably, 1 exhibited NIR photoluminescence at 1068 nm with a fluorescence lifetime of 1.920 μs, and the Nd³⁺ ion acted as an activator of the NIR luminescence. This finding represents a significant step toward advanced NIR-emissive responsive dielectrics for optoelectronic applications.