Facile Assembly of High-Quality Organic-Inorganic Hybrid Perovskite Quantum Dot Thin Films for Bright Light-Emitting Diodes

Organic-inorganic hybrid perovskite (CH3NH3PbX3, X = Cl, Br or I) quantum dots (QDs) have shown superior optoelectronic properties and have been regarded as a most ideal material for next-generation optoelectronic devices, particularly for QDs-based light-emitting diodes (QLEDs). However, there are only a few reports on CH3NH3PbX3 QLEDs and the reported performance is still very poor, primarily due to the difficulties in the fabrication of high-quality compact QDs thin films. In this work, an electric-field-assisted strategy is developed for efficient fabrication of uniform CH3NH3PbBr3 QDs thin films with high photoluminescence quantum yields (PLQY, 80%-90%) from dilute CH3NH3PbBr3 QDs suspensions (approximate to 0.1 mg mL(-1)) within 5 mins. Benefited from the high-quality CH3NH3PbBr3 QDs thin films, the corresponding QLEDs deliver a highly bright green emission with maximum luminances of 12450 cd m(2). Furthermore, a current efficiency of 12.7 cd A(-1), a power efficiency of 9.7 lm W-1, and an external quantum efficiency (EQE) of 3.2% were acheived by enhancing the hole injection. This performance represents the best results for CH3NH3PbBr3 QDs-based QLEDs reported to date. These results indicate an important progress in the fabrication of high-performance CH3NH3PbX3 QLEDs and demonstrate their huge potential for next-generation displays and lighting.