Emission Recovery and Stability Enhancement of Inorganic Perovskite Quantum Dots.

Inorganic lead halide perovskite quantum dots (PQDs), especially red emission PQDs, are well-known to easily lose their luminescence emission with time, which shows from strong emission of fresh PQDs to no emission of aged PQDs. Here, we demonstrate that trioctylphosphine (TOP) can effectively and instantly recover the luminescence emission of aged red PQDs, making the "dead" PQDs "reborn". Furthermore, TOP also works to improve the emission intensity of freshly synthesized PQDs. In this process, TOP does not make any detectable structural changes to PQDs. Besides, TOP can effectively enhance the stability of PQDs against long-term storage, temperature, UV irradiation, and polar solvents. This unusual emission recovery and stability enhancement by TOP shall promote the understanding of particle surface conditions and the development of PQD devices.