White light-emitting diodes based on carbon dots and Mn-doped CsPbMnCl nanocrystals.

CsPbX perovskite nanocrystals (NCs) are becoming a promising material for optoelectronic devices that possess an optically tunable bandgap, and bright photoluminescence. However, the toxic Pb is not environmentally friendly and the quantum yield (QY) of blue emitting NCs is relatively low. In addition, the red emitting perovskite containing iodine is not stable under light illumination. In this paper, high QY, blue emitting, non-toxic fluorescent nanomaterial carbon dots and orange-emitting CsPbMnCl NCs with partial Pb replacement are combined to fabricate white light-emitting diodes (WLEDs). A WLED with color coordinates of (0.337, 0.324) and a correlated color temperature of 4804 K is fabricated. Compared to red emitting perovskite containing iodine, the CsPbMnCl NCs are stable no matter whether they are stored in the air or exposed under ultraviolet light. Therefore, the as-fabricated WLED shows good color stability against increasing currents and long-term working stability.