Aggregation‐Induced Emission Features of Organometal Halide Perovskites and Their Fluorescence Probe Applications

Organometal hybrid perovskites exhibit tunable absorption and photoluminescence spectra that originate from the adjustable excitons of the self‐assembled quantum‐well structures. The aggregation‐induced emission (AIE) features of (RNH 3 ) 2 PbI 4 (R = alkyl, C n H 2 n +1 , n = 4, 12, 16, 18) as well as their reversible photoluminescence response to pH value are demonstrated. This interesting phenomenon correlates with the formation of quantum‐well structure, which is a novel AIE mechanism. The temperature sensors based on organometal hybrid perovskites are also investigated. The combination of high sensitivity (1.3% K −1 ) and good reversibility (>500 cycles) of organometal halide perovskites to temperature in a large temperature range (0–80 °C) makes them to be versatile systems for the temperature sensor applications. Furthermore, as a proof of concept, the application of organometal hybrid perovskites in 2D spatial imaging and NIR light detection is also presented.