Template-less synthesis of hollow carbon nanospheres for white light-emitting diodes

• We developed a novel method to synthesize HCNs.
• The growth temperature was as low as 160 °C.
• The luminescence quantum yield of HCNs was determined to be 35%, which is relatively high.
• White light emission was demonstrated by using the obtained HCNs as color converter with the commercial LED.
• We developed a facile coating approach to make white light emitting device.

A novel approach is demonstrated on the synthesis of hollow carbon nanospheres (HCNs) and their applications as color converter for white light-emitting diodes. HCNs were synthesized in a hydrothermal process using hexamethylenetetramine as precursor. The synthesis involves a template-less and one-step aqueous method for the first time, which enables the growth of HCNs with the temperature as low as 160 °C. HCNs solutions exhibit strong yellow-green emission under ultraviolet light excitation and possess typical excitation-dependent photoluminescence (PL) behavior as carbon nanoparticles. We also used a facile coating method to coat a blue LED with HCNs layer which plays a role as color-converted phosphor. The LED shows bright white light, and the spectrum involves two main components, one from the blue LED chip centered at 455 nm and one from HCNs centered at 520 nm.

Figure optionsDownload as PowerPoint slide