Zn-vacancy induced violet emission in p-type phosphorus and nitrogen codoped ZnO thin films grown by pulsed laser deposition

We report on the growth of violet emitting p-type ZnO thin films, with phosphorous (P) and nitrogen (N) codoping, using pulsed laser deposition. XPS studies show that the phosphorous is substituted at Zn site, whereas nitrogen is substituted at oxygen site. Hall measurements confirmed the p-type nature in codoped ZnO thin films. I-V characteristics of the heterojunction formed by n-Si and P, N: ZnO showed rectifying nature. Strong violet emission in PL spectra is attributed to the formation of zinc vacancies. We propose a defect complex, (PZn-VZn-4NO), which acts as an effective acceptor in the P and N codoped ZnO.