Organometal Halide Perovskite Quantum Dot Light-Emitting Diodes

Organometal halide perovskites quantum dots (OHP-QDs) with bright, color-tunable, and narrow-band photoluminescence have significant advantages in display, lighting, and laser applications. Due to sparse concentrations and difficulties in the enrichment of OHP-QDs, production of large-area uniform films of OHP-QDs is a challenging task, which largely impedes their use in electroluminescence devices. Here, a simple dip-coating method has been reported to effectively fabricate large-area uniform films of OHP-QDs. Using this technique, multicolor OHP-QDs light-emitting diodes (OQ-LEDs) emitting in blue, blue-green, green, orange, and red color have been successfully produced by simply tuning the halide composition or size of QDs. The blue, green, and red OQ-LEDs exhibited, respectively, a maximum luminance of 2673, 2398, and 986 cd m(-2) at a current efficiency of 4.01, 3.72, and 1.52 cd A(-1), and an external quantum efficiency of 1.38%, 1.06%, and 0.53%, which are much better than most LEDs based on OHP films. The packaged OQ-LEDs show long-term stability in air (humidity approximate to 50%) for at least 7 d. The results demonstrate the great potential of the dip-coating method to fabricate large-area uniform films for various QDs. The high-efficiency OQ-LEDs also demonstrate the promising potential of OHP-QDs for low-cost display, lighting, and optical communication applications.