Large-area color controllable remote carbon white-light light-emitting diodes

We disperse carbon nanodots (C-dots), which can be achieved by decomposing organic acid in silane coupling agent, in epoxy oligomer to realize large-area C-dots film on any transparent substrate. Due to the similarity in solubility parameters between C-dots and epoxy resin, aggregation of C-dots in epoxy resin is suppressed. It is found that the C-dots films can support high conversion efficiency (>60%) white-light emission under 460 nm illumination. In addition, the corresponding correlated color temperature can be varied between 2500 and 10,000 K by controlling the thickness of the C-dots film. We also verify that the absolute performance of C-dots film is compatible with that of the commercial available phosphor film.