Light-Emitting Diode Based on ZnO by Plasma-Enhanced Metal–Organic Chemical Vapor Deposition Employing Microwave Excited Plasma

In this paper we describe the growth of nitrogen doped zinc oxide (ZnO) films on single crystal ZnO substrates by plasma-enhanced metal–organic chemical vapor deposition (PE-MOCVD) employing microwave excited high-density plasma. We used Dimethylzinc (DMZ) as a Zinc precursor, and six different types of oxygen and nitrogen precursors: O2+N2, NO, N2O, O2+NH3, NO2, and O2. This paper considers the effects of nitrogen precursor material and utilizing the plasma on the structural properties and the nitrogen concentration by atomic force microscope and secondary ion mass spectrometry. It was only when using plasma and NO2 that the nitrogen (N) doped ZnO film with the steps and terraces surface structure of two-dimensional growth could be formed by our growth method. Furthermore, we fabricated a homostructural LED comprising the N-doped ZnO film and n-type ZnO substrate, and we achieved electroluminescence (EL) in forward bias at room-temperature (RT) and the current–voltage rectifying characteristics.