One‐Pot Exfoliation of Graphitic C3N4 Quantum Dots for Blue QLEDs by Methylamine Intercalation

Abstract Here, a simplified synthesis of graphitic carbon nitride quantum dots (g‐C 3 N 4 ‐QDs) with improved solution and electroluminescent properties using a one‐pot methylamine intercalation–stripping method (OMIM) to hydrothermally exfoliate QDs from bulk graphitic carbon nitride (g‐C 3 N 4 ) is presented. The quantum dots synthesized by this method retain the blue photoluminescence with extremely high fluorescent quantum yield (47.0%). As compared to previously reported quantum dots, the g‐C 3 N 4 ‐QDs synthesized herein have lower polydispersity and improved solution stability due to high absolute zeta‐potential (−41.23 mV), which combine to create a much more tractable material for solution processed thin film fabrication. Spin coating of these QDs yields uniform films with full coverage and low surface roughness ideal for quantum dot light‐emitting diode (QLED) fabrication. When incorporated into a functional QLED with OMIM g‐C 3 N 4 ‐QDs as the emitting layer, the LED demonstrates ≈60× higher luminance (605 vs 11 Cd m −2 ) at lower operating voltage (9 vs 21 V), as compared to the previously reported first generation g‐C 3 N 4 QLEDs, though further work is needed to improve device stability.