Nanowire LED simulation, illustration. Model of a nanowire-based light-emitting diode showing that adding a bit of aluminium to the shell layer (black) directs all recombination of electrons and holes (spaces for electrons) into the nanowire core (multicolored region), producing intense light. This research was carried out at the Physical Measurement Laboratory (PML) of the National Institute of Standards and Technology (NIST). Image published in 2019.