Solvent-Induced Galvanoluminescence of Metal-Organic Framework Electroluminescent Diodes

Abstract

Alternating current (AC) electroluminescent diodes were fabricated from MOF-5, a metal organic framework consisting of tetrahedral [Zn4O]6+ units linked by 1,4-benzenedicarboxylate ligands. An additional insulating layer was incorporated to prevent formation of electrical shorts. The electroluminescence spectrum was dramatically red-shifted with respect to the photoluminescence spectrum. By deliberately varying trapped solvent molecules, we demonstrate that the light emission does not originate from MOF-5 but is due to galvanoluminescence, emission of weak optical radiation in the visible region that occurs during anodic oxidation of the Al top electrode in contact with electrolytes.