Spin-Valley-Locked\nElectroluminescence for High-Performance\nCircularly Polarized Organic Light-Emitting Diodes

Circularly polarized (CP) organic light-emitting diodes\n(OLEDs)\nhave attracted attention in potential applications, including novel\ndisplay and photonic technologies. However, conventional approaches\ncannot meet the requirements of device performance, such as high dissymmetry\nfactor, high directionality, narrowband emission, simplified device\nstructure, and low costs. Here, we demonstrate spin-valley-locked\nCP-OLEDs without chiral emitters but based on photonic spin–orbit\ncoupling, where photons with opposite CP characteristics are emitted\nfrom different optical valleys. These spin-valley-locked OLEDs exhibit\na narrowband emission of 16 nm, a high external quantum efficiency\nof 3.65%, a maximum luminance of near 98,000 cd/m<sup>2</sup>, and\na <i>g</i><sub>EL</sub> of up to 1.80, which are among the\nbest performances of active single-crystal CP-OLEDs, achieved with\na simple device structure. This strategy opens an avenue for practical\napplications toward three-dimensional displays and on-chip CP-OLEDs.