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

Abstract

n - Zn 1 − x Mg x O ∕ i - Zn O ∕ Si O x ∕ 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 460nm was observed at room temperature when a positive bias of ∼4V 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.