Large-area and efficient perovskite light-emitting diodes via low-temperature blade-coating

Large-area light-emitting diodes (LEDs) fabricated by mass-production techniques are needed for low-cost flat-panel lighting. Nevertheless, it is still challenging to fabricate efficient large-area LEDs using organic small molecules (OLEDs), quantum dots (QLEDs), polymers (PLEDs), and recently-developed hybrid perovskites (PeLEDs) due to difficulties controlling film uniformity. To that end, we report sol-gel engineering of low-temperature blade-coated methylammonium lead iodide (MAPbI(3)) perovskite films. The precipitation, gelation, aging, and phase transformation stages are dramatically shortened by using a diluted, organoammonium-excessed precursor, resulting in ultra-flat large-area films (54cm(2)) with roughness reaching 1nm. The external quantum efficiency of doctor-bladed PeLEDs reaches 16.1%, higher than that of best-performing blade-coated OLEDs, QLEDs, and PLEDs. Furthermore, benefitting from the throughput of the blade-coating process and cheap materials, the expected cost of the emissive layer is projected to be as low as 0.02 cents per cm(2), emphasizing its application potential. Fabrication of efficient large-area perovskite light emitting diodes catering towards mass-production is hampered by the difficulty in getting homogenous uniform films and the high cost. Here, the authors demonstrate sol-gel engineering of low-temperature blade-coated perovskite films which can overcome these limitations.

Automated summary

Efficient large-area perovskite light emitting diodes for mass production are hindered by difficulties in obtaining uniform films and high costs. The authors demonstrate sol-gel engineering of low-temperature blade-coated perovskite films, which can address these limitations.