High mobility formation of p-type Al doped ZnO:N films annealed under NH3 ambient

High mobility p-type Al doped ZnO:N thin films have been efficiently realized by utilizing the double annealing process under different atmosphere ambients NH3 and N2. The co-doped films were deposited on to sapphire substrates using a spin coating method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, Hall measurements, and photoluminescence (PL). Experimental results confirmed the polycrystalline nature of the films. Incorporation of nitrogen in the ZnO lattice has also been confirmed by the Raman tool. The Al doped ZnO:N film showed an excellent p-type behavior with high mobility, hole concentration and low resistivity and their values were 198.8 cm2 V−1 s−1, 6.083×1017 cm−3 and 5.16×10−2 Ω cm, respectively. Photoluminescence was observed in the visible range.

► Use of different annealing atmospheres such as NH3 and N2. ► Enhancement of p-type conductivity owing to these atmospheres. ► Incorporation of nitrogen in ZnO lattice. ► Confirmation of enhancement of acceptor bound exciton from PL. ► High c-axis orientation.