Polycarbonate light guide plates with embedded quantum dots fabricated by large-scale injection moulding for wide colour gamut displays

A fabrication process of polycarbonate (PC) light guide plate (LGP) incorporating fluorescent quantum dots (QDs) is presented in this study. QD-PC composite pellets with dimension of 500 to 2500 μm were first prepared from a mixture of polyethylene-treated QDs and PC resin powder, followed by injection moulding to form a QD-LGP between 340 and 295 °C. The fabricated QD-LGPs demonstrated dual functions of light guiding and QD colour conversion, which is conventionally provided by a LGP covered with an additional QD diffuser film. By directly embedding QDs into a LGP, it was found that a rather low cadmium content around 41 ppm was sufficient to provide a uniform backlighting for a liquid-crystal display with a colour gamut of ~115% NTSC standard.