Improved emission efficiency of electroluminescent device containing nc-Si/SiO 2 multilayers by using nano-patterned substrate

Nanocrystalline Si/SiO2 multilayers-based electroluminescent devices were prepared on nano-patterned p-Si substrates which were fabricated by nano-sphere lithography technique. The formed nano-patterned substrate contains periodic Si nano-cone arrays with the height of 80~95 nm and the diameter around 220 nm. The turn-on voltage of the luminescent device prepared on nano-patterned substrate is 3 V while the electroluminescence intensity is increased by over one order of magnitude compared to that of device prepared on flat substrate. The enhancement of the light emission can be attributed to the improved extraction efficiency of emission light as well as the high carrier-injection efficiency.