Efficient cyan‐emitting solid carbon dots (CDs) were synthesized via a one‐pot hydrothermal method. The obtained solid CDs show a broad absorption from 270–460 nm with a maximum around 400 nm, and emit intense cyan light around 500 nm with an internal photoluminescence quantum efficiency of 34.1 % under 400 nm excitation. The emission maximum of the solid CDs remains unchanged under 320–400 nm excitations. Compared with dilute aqueous of CDs (2.5 mg mL⁻¹), the emission of solid CDs shows an obvious red‐shift of 50 nm. The red‐shift is caused by resonant energy transfer due to larger spectral overlap and smaller interparticle distance, together with a new surface state caused by aggregation in solid CDs. A lamp with white LEDs was fabricated by dropping a mixture of solid CDs, CaAlSiN₃:Eu²⁺ and silicon resin on the top of a near‐ultraviolet LED chip. Under an operating current of 20 mA, the as‐fabricated white LED generates a high‐quality, warm white light with a color rendering index of 86.1, a color temperature of 4340 K, and a luminescence efficiency of 31.3 lm W⁻¹.

中文翻译：

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固态碳点对白光发光二极管的蓝绿色发射效率高

通过单锅水热法合成了有效的发蓝光固体碳点（CD）。所获得的固体CD在270–460 nm处显示出较宽的吸收，最大值在400 nm附近，并在500 nm处发出强烈的蓝绿色光，在400 nm激发下内部光致发光的量子效率为34.1％。固态CD的最大发射在320–400 nm激发下保持不变。与CD的稀水溶液（2.5 mg mL ^-1）相比，固体CD的发射显示出50 nm的明显红移。红移是由于较大的光谱重叠和较小的粒子间距离所引起的共振能量转移，以及由固态CD中的聚集所引起的新的表面状态。通过滴加固体CD CaAlSiN ₃的混合物来制造带有白色LED的灯：Eu ²⁺和硅树脂在近紫外LED芯片的顶部。在20 mA的工作电流下，预制的白光LED产生高质量的暖白光，其显色指数为86.1，色温为4340 K，发光效率为31.3 lm W ^-1。