Investigation on Charge Carrier Recombination of Hybrid Organic–Inorganic Perovskites Doped with Aggregation-Induced Emission Luminogen under High Photon Flux Excitation

A typical aggregation-induced emission luminogen (AIE-gen) is introduced into perovskite CH 3 NH 3 PbI 3 and the material and photophysical properties of hybrid films are investigated with absorption, X-ray diffraction, and steady-state photoluminescence (PL) characterization. When excited by a high photon flux (4.08 × 10 22 cm −2 s −1 ) laser beam (3.82 eV) at room temperature, the CH 3 NH 3 PbI 3 polycrystalline thin films exhibit dual emission locating at 1.64 eV ( P 1 ) and 1.59 eV ( P 2 ). The two PL peaks are attributed to free carrier (FC) recombination and exciton recombination, respectively. Additionally, an introduction of AIE-gen changes the peak value ratio of P 1 : P 2 , indicating the radiative recombination ratio of FCs versus excitons in perovskite films can be tuned with this method. Since recombination of FCs and excitons plays a key role in photovoltaic and luminescent devices, this finding helps to clarify the recombination behavior of photogenerated carriers in perovskites and promote their further applications in photoelectric devices.