Strong green-yellow electroluminescence from oxidized amorphous silicon nitride light-emitting devices

High efficiency luminescent amorphous silicon nitride films grown at room temperature with subsequent plasma oxidation were used as the active layers in the electroluminescent devices. A strong uniform green-yellow light emission from the devices was realized under forward biased conditions. It was found that the turn-on voltage could be reduced to as low as 6 V while the electroluminescence (EL) intensity is significantly enhanced by two to four times by using p-type Si anode instead of indium tin oxide substrate under the same forward voltage. Furthermore, the EL peak position is blueshifted from 560 to 540 nm, which is more close to that of the corresponding photoluminescence peak. The origin of light emission is suggested to be the same kind of luminescent centers related to the Si-O bonds. (c) 2007 American Institute of Physics.