P-type nitrogen-doped ZnO thin films on sapphire ( 1 1 2 ¯ 0 ) substrates by remote-plasma-enhanced metalorganic chemical vapor deposition

Nitrogen doped ZnO films were successfully grown, by remote-plasma-enhanced metalorganic chemical vapor deposition (RPE-MOCVD), having p-type conduction with carrier concentration ranging from 10 13 to 10 15 cm −3 and resistivity of the order of 10 −1–10 2 Ω cm. ZnO and ZnO:N films on sapphire substrate were characterized by Fourier transform infrared (FT-IR) and Raman spectroscopy (RS). Nitrogen-related RS modes emerged at 289, 587 and 653 cm −1. Application of FT-IR for characterization, specially for films (ZnO and ZnO:N) deposited on a-plane sapphire was used as a new concept. IR modes of carbon–nitrogen complexes (CN, CC, and CO), NO and OH were observed. The complexes created in as-grown films were weakened due to annealing leading to change in conductivity to p-type. ZnO:N/ZnO (p–n) junctions were fabricated and rectifying I–V characteristics were obtained confirming attainment of p-type conduction.