Multicolor fluorescent light emitting diodes based on cesium lead halide perovskite quantum dots
High quantum yield, narrow full width at half maximum and tunable emission color of perovskite quantum dots (QDs) make this kind of material good prospects for light emitting diodes (LEDs) However, the relatively poor stability under high temperature and air condition limits the device performance. To overcome this issue, the liquid type packaging structure in combination with blue LED chip was employed to fabricate the fluorescent perovskite quantum dot based LEDs. A variety of monochromatic LEDs with green, yellow, reddish orange, and red emission were fabricated by utilizing the inorganic cesium lead halide perovskite quantum dots as the color conversion layer, which exhibited the narrow full width at half maximum <35 nm) the relatively high luminous efficiency (reaching 75.5 lm/W) and the relatively high external quantum efficiency (14.6% making it the best performing perovskite LEDs so far. Compared to the solid state LED device, the liquid type LED devices exhibited excellent color stability a.