Deep-blue light-emitting diodes (LEDs) (emitting at wavelengths of less than 450 nm) are important for solid-state lighting, vivid displays and high-density information storage. Colloidal quantum dots, typically based on heavy metals such as cadmium and lead, are promising candidates for deep-blue LEDs, but these have so far had external quantum efficiencies lower than 1.7%. Here we present deep-blue light-emitting materials and devices based on carbon dots. The carbon dots produce emission with a narrow full-width at half-maximum (about 35 nm) with high photoluminescence quantum yield (70% ± 10%) and a colour coordinate (0.15, 0.05) closely approaching the standard colour Rec. 2020 (0.131, 0.046) specification. Structural and optical characterization, together with computational studies, reveal that amine-based passivation accounts for the efficient and high-colour-purity emission. Deep-blue LEDs based on these carbon dots display high performance with a maximum luminance of 5,240 cd m⁻² and an external quantum efficiency of 4%, notably exceeding that of previously reported quantum-tuned solution-processed deep-blue LEDs.

深蓝色发光二极管（LED）（以小于450 nm的波长发射）对于固态照明，生动的显示和高密度信息存储非常重要。胶体量子点通常基于镉和铅等重金属，是深蓝色LED的有希望的候选物，但到目前为止，它们的外部量子效率低于1.7％。在这里，我们介绍了基于碳点的深蓝色发光材料和器件。碳点产生的发射具有半峰宽（约35 nm）的窄全宽，具有高的光致发光量子产率（70％±10％）和色坐标（0.15，0.05），非常接近标准Rec。2020（0.131，0.046）规范。结构和光学表征以及计算研究，揭示基于胺的钝化是有效和高色纯度发射的原因。基于这些碳点的深蓝色LED表现出最高的性能，最大亮度为5,240 cd m^-2，外部量子效率为4％，显着超过先前报道的量子调谐溶液处理的深蓝色LED的效率。