Color-by-Blue QD-Emissive LCD Enabled by Replacing RGB Color Filters with Narrow-Band GR InP/ZnSeS/ZnS QD Films

Abstract

Color-by-blue quantum dot (QD)-emissive liquid-crystal displays (LCDs) with eco-friendly, green, red (GR) InP/ZnSeS/ZnS QD films are introduced to overcome the disadvantages of conventional color-by-white color filter (CF)-assisted LCDs, such as a narrow viewing angle, low external device efficiency of these types of LCDs, and a restricted color gamut. In this study, the color-by-blue InP-based QD-emissive LCD consists of a blue (B) light-emitting diode (LED) and GR InP-based QD films sandwiched between a light recycling filter and a long-wavelength pass dichroic filter. The GR InP-based QDs are synthesized with a high photoluminescence quantum yield (>77%) and narrow bandwidth (<40 nm), which are suitable for display applications. The overall enhancement of InP-based QD-emissive LCDs, in this case by the enhanced efficiency of a blue LED backlight transmitted through the LC shutter compared to a white LED backlight and the improved efficiency of the enlarged color gamut, is 2.42 times that of a conventional red, green, and blue (RGB) CF-LCD with a GR phosphor-converted (pc)-LED (a B LED + R K2SiF6:Mn + G beta-SiAlON:Eu phosphor) backlight. Therefore, this considerable enhancement of the external efficiency of a QD-emissive LCD makes it more feasible as a replacement for conventional RGB CF-assisted LCDs.