All‐Thermally Evaporated Blue Perovskite Light‐Emitting Diodes for Active Matrix Displays

Abstract With the rapid progress of perovskite light‐emitting diodes (PeLEDs), the large‐scale fabrication of active matrix PeLED displays (AM‐PeLEDs) is gaining increasing attention. However, the integration of high‐resolution PeLED arrays with thin‐film transistor backplanes remains a significant challenge for conventional spin‐coating techniques. Here, the demonstration of large‐area, blue‐emitting AM‐PeLEDs are demonstrated using a vacuum deposition technique, which is regarded as the most effective route for organic light‐emitting diode displays. By the introduction of an in situ passivation strategy, the defects‐related nonradiative recombination is largely suppressed, which leads to an improved photoluminescence quantum yield of vapor‐deposited blue‐emitting perovskites. The as‐prepared blue PeLEDs exhibit a peak external quantum efficiency of 2.47% with pure‐blue emission at 475 nm, which represents state‐of‐the‐art performance for vapor‐deposited pure‐blue PeLEDs. Benefiting from the excellent uniformity and compatibility of thermal evaporation, the 6.67‐inch blue‐emitting AM‐PeLED display with a high resolution of 394 pixels per inch is successfully demonstrated. The demonstration of blue‐emitting AM‐PeLED display represents a crucial step toward full‐color perovskite display technology.