Effect of annealing temperature on structural, electrical and optical properties of B–N codoped ZnO thin films

The B–N codoped p-type ZnO thin films have been prepared by radio frequency magnetron sputtering using a mixture of nitrogen and oxygen as sputtering gas. The effect of annealing temperature on the structural, electrical and optical properties of B–N codoped films was investigated by using X-ray diffraction, Hall-effect, photoluminescence and optical transmission measurements. Results indicated that the electrical properties of the films were extremely sensitive to the annealing temperature and the conduction type could be changed dramatically from n-type to p-type, and finally changed to weak p-type in a range from 600 °C to 800 °C. The B–N codoped p-type ZnO film with good structural, electrical and optical properties can be obtained at an intermediate annealing temperature region (e.g., 650 °C). The codoped p-type ZnO had the lowest resistivity of 2.3 Ω cm, Hall mobility of 11 cm2/Vs and carrier concentration of 1.2 × 1017 cm− 3.

► The p-type ZnO thin films with low resistivity are obtained by B–N codoping method.
► The p-type character is identified by rectification character of ZnO homojunction.
► The electrical properties are extremely sensitive to the annealing temperature.
► The p-type ZnO with good properties is obtained at middle annealing temperature.