Structural Engineering\nfor Efficient Transparent Vacuum-Deposited\nPerovskite Light-Emitting Diodes toward Intelligent Display

Perovskite light-emitting diodes (PeLEDs) have attracted\nsignificant\ninterest in next-generation intelligent displays. Vacuum deposition\nis a promising method for integrating PeLEDs into intelligent displays\ndue to its high manufacturability and easy pixelation, as proven in\nindustrial organic light-emitting diode production. However, achieving\nspatially confined grains with optimized crystal remains challenging\nin vacuum-deposited perovskite. Here, a trisource coevaporation strategy\nis proposed to introduce MABr to form the MA<sub><i>x</i></sub>Cs<sub>1–<i>x</i></sub>PbBr<sub>3</sub> structure\nwith carriers’ spatial confinement and defect suppression as\nwell. This approach enables PeLEDs to contain excellent external quantum\nefficiency (EQE), which is nearly 10-fold as the untreated device.\nBased on this, we realize the first reported vacuum-deposited transparent\nPeLEDs with double-sided emission and an amazing maximum EQE of 7.6%\nby replacing Al with an optimized Ag:Mg electrode. These transparent\nPeLEDs are integrated into a bifunctional intelligent display device\nwith both accurate heart rate detection and imaging display, which\nexhibit bright patterned emission and accurate heart rate detection.