Intrinsic Hole Mobility in Luminescent Metal-Organic Frameworks and Its Application in Organic Light-Emitting Diodes.

Most metal-organic frameworks (MOFs) lack charge mobility, which is crucial for realizing their use in optoelectronic applications. This work proposes the design of a MOF using triarylamine-based ligands (Zr-NBP) as the lone pair electron spacer to enhance the hole mobility in the MOF while maintaining its luminescent properties. Zr-NBP has strong fluorescence with a good hole mobility of 1.05×10 -6  cm 2  V -1  s -1 , which is comparable to organic materials used in optoelectronic devices. We also employed a Zr-NBP nanofilm in the pure phase as both a non-doped emissive layer and a hole-transporting layer within organic light-emitting diodes (OLEDs). The obtained OLED device produced a bright green light with a low turn-on voltage of 3.9 V. This work presents an advance in developing the electronic properties of MOFs by modifying the chemical properties of its building blocks, and will likely inspire further design of MOF materials as active layers in optoelectronic devices.