Multi‐Color Magnetic Circularly Polarized Luminescence from Achiral Perovskite (Cs+Pb2+X3) Quantum Dots

High‐performance optoelectronic materials require luminescent materials capable of intense photoluminescence (PL). However, controlling the optical properties of luminescent materials requires complex synthesis and purification procedures. Herein, we propose a simple method for obtaining circularly polarized luminescence from achiral inorganic quantum dots. This method involves applying north‐up and south‐up 1.7 T magnetic fields at 25 °C to five types of achiral antimagnetic perovskite‐Pb‐quantum dots in a solution state. The wavelengths of magnetic circularly polarized luminescence (MCPL) and PL of achiral perovskite‐Pb quantum dots were successfully controlled according to the type and composition ratio of halogen ions. The magnitude of MCPL, gMCPL, was on the order of |gMCPL|=10−3 in a wavelength range of 406–697 nm. Although the perovskite‐Pb‐quantum dots were achiral, the rotation direction of the MCPL could be controlled by varying the direction of the applied magnetic field. In toluene, octane, and hexane solutions of achiral soluble antimagnetic perovskite‐Pb quantum dots, magnetic circularly polarized luminescence (MCPL) was emitted in both rotational directions when 1.7 T north‐up and south‐up magnetic fields were applied at 25 °C. The color and wavelength of MCPL could be controlled by changing the type and composition of the halide ions of the quantum dots.