Highly Efficient and Stable Binary‐Doped Narrowband Blue OLEDs Enabled by a Single‐Component Host Matrix with a Spatial Bipolarity Configuration

Abstract Highly efficient and stable narrowband blue organic light‐emitting diodes (OLEDs) are vital for high‐definition displays, yet the achievement of such devices via a concise binary‐doped fabrication architecture remains challenging. Herein, an effective and robust single‐component host matrix with a spatial bipolarity configuration is developed for high‐performance OLEDs. Two elaborately designed molecules are constructed on a non‐conjugated silyl linker connecting boron–oxygen and carbazole‐derived groups. The boron–oxygen electron‐accepting and carbazole‐based electron‐donating moieties exhibit synergistic and complementary group functions, achieving wide bandgaps of excited energy states, along with thermally activated delayed fluorescence and bipolar carrier transport features. Following the incorporation of a blue multiresonant guest emitter, the doped emissive film showcases enhanced horizontal orientation and photoluminescent efficiency. The binary‐doped narrowband blue OLEDs achieve the record maximum external quantum efficiency of 42.3% with low roll‐off (efficiency of 38.3% at 1,000 cd m −2 ), and the improved operational stability with a half‐lifetime of 3076 h at an initial luminance of 100 cd m −2 . This study reveals that the utilization of a spatial bipolarity host matrix is a promising approach to realize narrowband blue OLEDs with concise architecture and high performance.