Giant enhancement of the n-type conductivity in single phase p-type ZnO:N thin films by intentionally created defect clusters and pairs

• P-type conductivity with very high transparency in visible region of nitrogen doped zinc oxide (ZnO:N) thin films.
• A systematic p- to n-type conductivity transformation and about four orders of magnitude enhancement of n-type conductivity.
• The intentionally induced complex defects such as VO/Zni clusters and VZn–VO defects pairs are mainly ascribed as the donor defects in ZnO and used to explain the p- to n-type transformation and the giant enhancement in the conductivity of films.

The p-type conductivity with very high transparency in visible region of electromagnetic spectrum from nitrogen doped zinc oxide (ZnO:N) thin films is reported and the origin of p-type conductivity is attributed to the formation of complex zinc interstitial–nitrogen substituted oxygen (Zni–NO) centers. The films are irradiated using energetic ions for inducing the high density of defects/defect clusters in the lattice for increasing the conductivity of the films. A systematic change in nature of charge carriers from p- to n-type and about four orders of magnitude enhancement of n-type conductivity is observed with increase in the fluence of irradiation. The intentionally induced complex defects such as VO/Zni clusters and VZn–VO defects pairs are mainly ascribed to the donor defects. These induced defects also act as the compensatory defects for the p-type charge carriers at low fluences and give rise to the giant enhancement in the n-type conductivity of films at higher fluence of irradiation.