Realization of n-Zn1-xMgxO/i-ZnO/SiOx/n+-Si heterostructured n-i-n light-emitting diodes by low-cost ultrasonic spray pyrolysis

n-Zn1-xMgxO/i-ZnO/SiOx/n(+)-Si heterostructured light-emitting diodes have been demonstrated by low-cost ultrasonic spray pyrolysis. The current-voltage measurement shows typical characteristics of a back-to-back diode due to the double Schottky barriers induced by the SiOx layer. Blue electroluminescence peaking at 460 nm was observed at room temperature when a positive bias of similar to 4 V was applied on the Si substrate. The electroluminescence is suggested to be dominated by the donor-acceptor pair recombination in the i-ZnO layer, where the holes were injected from the valence band of Si into the acceptor level of i-ZnO. (c) 2007 American Institute of Physics.