Ni/Au contact to silicon quantum dot light-emitting diodes for the enhancement of carrier injection and light extraction efficiency

The effect of Ni/Au metal contact on the carrier injection and the electroluminescence of silicon quantum dot light-emitting diodes (LEDs) was investigated. An LED with an annealed Ni/Au contact at 400 degrees C in air showed a lower threshold voltage compared to that of an as-deposited Ni/Au contact by forming a nickel silicide, which has a lower work function than Ni at the interface between metal layers and silicon nitride. The optical output power of the LED with the annealed Ni/Au contact was also increased due to a highly transparent NiO layer and a lowly resistant Au layer. (c) 2006 American Institute of Physics.