Since colloidal nanocrystals (NCs) were integrated as green and red sources for LCD displays, the next challenge for quantum dots has been their use in electrically driven light emitting diodes (LEDs). Among various colloidal nanocrystals, nanoplatelets (NPLs) appeared as promising candidates for light emitting devices because their two-dimensional shape allows a narrow luminescence spectrum, directional emission and high light extraction. To reach high quantum efficiency it is critical to grow core/shell structures. High temperature growth of the shells seems to be a better strategy than previously reported low temperature approaches to obtain bright NPLs. Here, we synthesize CdSe/CdZnS core/shell NPLs whose shell alloy content is tuned to optimize the hole injection in the LED structure. The obtained LED has exceptionally low turn-on voltage, long-term stability (>3100 h at 100 Cd.m-2), external quantum efficiency above 5% and luminance up to 35000 cd.m-2. We study the low-temperature performance of the LED and find that there is a delay of droop in terms of current density as temperature decreases. In the last part of the paper, we design a large LED (56 mm2 emitting area) and test its potential for LiFi-like communication. In such approach, the LED is not only a lightning source but also used to transmit a communication signal to a PbS quantum dot solar cell used as a broad band photodetector. Operating conditions compatible with both lighting and information transfer have been identified. This work paves the way toward an all nanocrystal-based communication setup.