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.