Synthesis of High Molecular Weight 1,4-Polynaphthalene for Solution-Processed True Color Blue Light Emitting Diode

Efficient light emitting diodes (LEDs) derived from organic π-conjugated polymers are in the center of light generating research. Facile fabrication of true color blue LEDs is challenging. Herein, for the first time, we report the synthesis of highly soluble new π-conjugated polymers 1,4-polynaphthalenes with high molecular weight following a Ni(0)-mediated Yamamoto coupling reaction. The designed polymer shows a color pure blue luminescence with a high quantum yield of ∼80% in solution and ∼34% in thin film. We demonstrate solution-processed fabrication and ambient condition operation of LEDs using 1,4-polynaphthalene as the active layer. True color blue electroluminescence from the LEDs with CIE coordinates (0.16, 0.08) meets the criteria of the National Television Standards Committee (NTSC) for efficient displays.