Rare Earth-Free Luminescent Materials for WLEDs: Recent Progress and Perspectives

The development and application of white light-emitting diode (WLED) lighting technology are of great significance for reducing energy consumption. Commonly used WLED devices rely on the use of rare earth luminescent materials. However, rare earth elements are nonrenewable resources, and mining and refining processes have an adverse impact on the environment. In recent years, new white light-emitting luminescent materials that do not contain rare earth elements have been developed, such as quantum dots, fluorescent carbon dots, perovskite luminescent materials, organic luminescent materials, and metal–organic framework materials, among others, some of which are successfully applied in the development of WLEDs. Herein the latest progress in this research field is reviewed, analyzing the construction of practical WLED devices and comparing the characteristics of newly developed rare earth-free luminescent materials. Last, the future development prospects in this field are described.