Enhanced magneto-optical sensitivity in CsPbBr₃ perovskites via Cr³⁺ ions doping

The magneto-optical effect provides a means of optical manipulation for materials and plays a significant role in optical signal modulation. However, the regulation of magneto-optical anisotropy remains challenging. This study reports the impact of Cr³⁺ doping on the optical anisotropy of CsPbBr₃ perovskite under a magnetic field. Experimental observations revealed that Cr³⁺ doping successfully induced dual emission peaks corresponding to the antiferromagnetic polaron (AMP) and the exciton magnetic polaron (EMP), resulting in a blue shift in the photoluminescence (PL) spectrum. Polarization-resolved PL measurements demonstrated that Cr³⁺ doping significantly enhanced the magnetic field sensitivity of CsPbBr₃. The optical anisotropy progressively transitioned towards isotropy with increasing magnetic field strength, with the AMP exhibiting stronger magnetic field sensitivity than the EMP. Furthermore, density functional theory (DFT) calculations indicated that Cr³⁺ doping substantially modified the electronic band structure of the material. These findings provide a viable strategy for tuning the magneto-optical anisotropy of lead halide perovskites, demonstrating significant potential in applications such as magneto-optical modulators and quantum sensing devices.