Growth of ZnO and ZnMgO nanorods on Si substrates by using ultrasonic spray pyrolysis

We demonstrate the growth of ZnO and ZnMgO nanorods on Si substrates through a two-step process without a catalyst by using a simple ultrasonic spray pyrolysis method. First, a ZnO thin film was deposited on a Si substrate to make a seed layer; then, ZnO and ZnMgO nanorods were deposited on that seed layer. ZnO and ZnMgO nanorods with a p-n junction were obtained by using nitrogen doping for p-type nanorods, and gallium doping for n-type nanorods. A distinct electroluminescence was observed at room temperature from the ZnO and the ZnMgO nanorod structures under forward bias conditions.