Comparison on the electroluminescence of Si-rich SiNx and SiOx based light-emitting diodes

Electroluminescence (EL) of the metal-insulator-semiconductor light-emitting diodes (MISLEDs) made by Si-rich SiNx and SiOx films with buried Si nanocrystals are compared. The SiNx facilitates carrier transport and EL from MISLED with turn-on current and voltage of 4 mu A and 12 V by reducing barrier heights at indium tin oxide /SiNx and SiNx/Si-nc interfaces. The SiNx MISLED exhibits larger charge loss rate of 12% within 200 s and shorter delay time of 3.86x10(-4) sec than SiOx one, which limit its external EL quantum efficiency by strong carrier escaping effect due to the insufficient carrier confinement in Si nanocrystals with low interfacial barriers. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3459144]