High-performance light-emitting diodes based on carbene-metal-amides

Adding a twist for enhanced performance The efficiency of organic light-emitting diodes (OLEDs) is fundamentally governed by the ratio of emissive singlet to dark triplet excitons that are formed from spin-polarized electron and hole currents within the material. Typically, this has set an upper limit of 25% internal quantum efficiency for OLEDs. Di et al. manipulated the ratio of spin states through a modification of process chemistry. They introduced a rotation of the molecular structure, which inverted the spin-state energetics and enhanced OLED performance. Science , this issue p. 159