Review—Application of Photoluminescent and Electroluminescent Metal-Organic Frameworks in White Light-Emitting Diodes

With less heat emission, longer lifetime, and high energy yield, light-emitting Diodes (LEDs) have been studied as a substitute for conventional light sources. Following various studies developing LED components based on semiconductors, organic materials, and polymers, LEDs based on a new class of materials called metal organic frameworks (MOFs) has been reported. Due to high tunability and multifunctionality of the novel organic-inorganic hybrid material, MOFs, white light-emitting diodes based on those materials, have the highest CRI and CIE coordinates nearest to (0.33, 0.33) (White light) among those reported. In this study, MOFs used for LED components are reviewed. It was found that MOFs are used for LED components in two main sectors, white phosphor and light emissive layer. MOFs used for light emissive layer exhibited electroluminescence by the presence of organic linkers, metals, and their interactions such as MLCT or LMCT. Several MOFs showed electroluminescence by guest molecules. The main hindrance for wide use of MOFs for LEDs are energy efficiency, lack of red light, and stabily. Studies to overcome those obstacles have been introduced. Based on those studies, we provide possible solutions for current challenges and various perspectives that MOF-based LEDs researcher should consider.