Improved electroluminescence from silicon nitride light emitting devices by localized surface plasmons

Enhanced electroluminescence (EL) from SiNx light emitting devices (LEDs) with an ITO/SiO2/SiNx/Ag/p/p+-Si/Al structure was observed. Comparing to SiNx LEDs without Ag islands layer, those with Ag islands layer could conduct a higher injection current and extract light more efficiently due to the roughness of Ag islands film. Moreover, the localized surface plasmons induced by Ag islands enhanced the radiative efficiency of LEDs, resulting in the EL enhancement of ~14. By the combination enhancement on light extraction efficiency, radiative efficiency, and current-injection efficiency, the external quantum efficiency of EL from SiNx LEDs was improved by at least one order of magnitude.