Mechanism of magnetic field-modulated luminescence from lanthanide ions in inorganic crystal: a review

The luminescence from lanthanide ions has potential applications in light emitting diodes, biomedical, solar cells, sensors, display, etc. However, the luminescence is suffered from the various problems, such as low luminescence efficiency and inharmonious wavelength for energy transfer. Magnetic field is an efficient method to modulate the wavelength and intensity of luminescence from lanthanide ions. Magnetic field redistributes the populated electrons in the excited states to tune the wavelength of lanthanide ions by Zeeman effect, mixing effect, and quantum confinement effect. Magnetic field enhances or suppresses the luminescence intensity by the administration of cross-relaxation, energy transfer, and Boltzmann population. In this review, we first introduce the various phenomena and mechanisms of magnetic field modulated downshift luminescence from lanthanide ions, including Zeeman effect, cross-relaxation, crystal structure, absorption, quantum confinement effect, and magnetic–optical hysteresis. Then, we explain the regulation of upconversion luminescence by magnetic field, containing energy transfer and mixing effect. Finally, different options regarding how to understand the mechanism of magnetic field-modulated luminescence from lanthanide ions in the future are outlined. Graphic abstract