Hybrid White Light Emitting Diode Based on Silicon Nanocrystals

A novel design of white light emitting diodes (WLEDs) emerges to meet the growing global demand for resource sustainability while preserving health and environment. To achieve this goal, a facile method is developed for the chemical synthesis of a luminescent silicon nanocrystal (ncSi) with a large Stokes shift between absorption and emission. The WLED is prepared by a simple spin-coating method, and contains a hybrid-bilayer of the ncSi and luminescent polymer in its device active region. Interestingly, a well-controlled ultrathin ncSi layer on the polymer makes possible to recombine electrons and holes in both layers, respectively. Combining red and blue-green lights, emitted from the ncSi and the polymer layers, respectively, produces the emission of white electroluminescence. Herein, a hybrid-WLED with a sufficiently low turn-on voltage (3.5 V), produced by taking advantages of the large Stokes shift inherent in ncSi, is demonstrated.