Dual-Emissive CsPbBr3@Eu-BTC Composite for Self-Calibrating Temperature Sensing Application

A dual-emissive optical sensor based on the fluorescence intensity ratio (FIR) technique has been demonstrated to have significant advantages of high sensitivity and reliability. Here, we designed and successfully prepared a self-calibrated optical luminescent thermometer of CsPbBr3 quantum dot (QD) encapsulated lanthanide metal–organic frameworks (Eu-BTC), and their phase compositions and luminescence properties have been characterized. Different thermo-response luminescence behaviors originating from the photoluminescence of CsPbBr3 QDs at 528 nm and the 5D0–7F2 emission of Eu3+ at 618 nm were investigated in the temperature range of 20–100 °C, in which the dual-emissive temperature-dependent emissions can serve as a ratiometric thermometer for accurate temperature monitoring applications. Significantly, the as-obtained CsPbBr3@Eu-BTC hybrid exhibited a high relative sensitivity (Sr) of 3.9% °C–1 at 20 °C and excellent temperature resolution of 0.004 °C in the measured temperature range, indicating its superiority as a ratiometric luminescent thermometer for temperature sensing. The related luminescent sensing mechanism of the CsPbBr3@Eu-BTC is also discussed, and this work provides an effective strategy for the rational design of a reliable and stable thermometer by integrating CsPbBr3 QDs and a carrier of a luminescent lanthanide organic framework.