Two-Dimensional Hybrid Perovskite with High-Sensitivity Optical Thermometry Sensors

Optical thermometry has gained significant attention due to its remarkable sensitivity and noninvasive, rapid response to temperature changes. However, achieving both high absolute and relative temperature sensitivity in two-dimensional perovskites presents a substantial challenge. Here, we propose a novel approach to address this issue by designing and synthesizing a new narrow-band blue light-emitting two-dimensional perovskite named (C₈H₁₂NO₂)₂PbBr₄ using a straightforward solution-based method. Under excitation of near-ultraviolet light, (C₈H₁₂NO₂)₂PbBr₄ shows an ultranarrow emission band with the full width at half-maximum (FWHM) of only 19 nm. Furthermore, its luminescence property can be efficiently tuned by incorporating energy transfer from host excitons to Mn²⁺. This energy transfer leads to dual emission, encompassing both blue and orange emissions, with an impressive energy transfer efficiency of 38.3%. Additionally, we investigated the temperature-dependent fluorescence intensity ratio between blue emission of (C₈H₁₂NO₂)₂PbBr₄ and orange emission of Mn²⁺. Remarkably, (C₈H₁₂NO₂)₂PbBr₄:Mn²⁺ exhibited maximum absolute sensitivity and relative sensitivity values of 0.055 K^-1 and 3.207% K^-1, respectively, within the temperature range of 80-360 K. This work highlights the potential of (C₈H₁₂NO₂)₂PbBr₄:Mn²⁺ as a promising candidate for optical thermometry sensor application. Moreover, our findings provide valuable insights into the design of narrow-band blue light-emitting perovskites, enabling the achievement of single-component dual emission in optical thermometry sensors.