Intriguing Electroplex System Based on All‐Thermally Evaporated Organic Small Molecule Donor and 0D Perovskite Acceptor

Abstract Although both organic and perovskite light‐emitting diodes (OLEDs and PeLEDs) are rapidly developed, OLEDs are more stable and PeLEDs possess larger carrier mobility compared with each other. Naturally, combining their respective advantages is crucial for the device photoelectric performances. Here, an intriguing electroplex system comprising an organic donor and a 0D perovskite (0D‐Cs 4 PbBr 6 ) acceptor is demonstrated by probing fingerprint magnetic field effects and transient/steady electroluminescence spectroscopies of control devices and Cs‐Pb‐Br films. Such a clear role division in this newly‐found electroplex system makes it possible to integrate their own advantageous properties into a single optoelectronic device (organic‐perovskite light‐emitting diodes, O‐Pe‐LEDs). Interestingly, the 0D‐Cs 4 PbBr 6 acceptor is transformed from the typical 3D CsPbBr 3 (3D‐CsPbBr 3 ) by annealing treatment and can revert to 3D‐CsPbBr 3 under atmospheric exposure. This reversible phase transition leads to abundant optical, electrical, and magnetic behaviors of O‐Pe‐LEDs. More importantly, these O‐Pe‐LEDs are fabricated by an all‐thermal evaporation deposition technique, which is demonstrated as the most feasible route for simultaneously achieving high‐resolution pixels and large‐scale production. Therefore, this innovation of organic‐perovskite electroplexes opens an unprecedented research direction for developing high‐performance commercial LEDs for lighting and flat‐panel displays.